Let's start with two assumptions.
#1 - Brooklyn will still have the worst record in the league at the trade deadline.
#2 - This draft is as good as "draftniks" claim. I've seen it suggested it could be a historically good draft. The top 7 are supposedly all exceptional talents and I've seen multiple people claim Fultz and Ball have a chance to be true NBA superstars.
Based on those two assumptions, I'm having a hard time thinking of a pre-lottery draft pick over the past 10+ years that is more valuable than the 2017 Brooklyn pick. Seriously.
You have to understand that not all drafts are created equally. There are bad drafts and good drafts. Top heavy drafts and deep drafts. And yes, I know that it's an unpredictable thing and drafts can often exceed or fall short of expectations. 2013, for instance, was widely considered a terrible draft. This was reflected in the fact that the #1 pick was Anthony Bennett. And yet, we now know several players from that draft are actually pretty darn good. Giannis at #15, Gobert at #27, McCollum at #10, etc. In retrospect, 2013 has some winners. But it doesn't change the fact that at the time, it was widely considered a weak draft. If we're considering the trade value of unprotected draft picks heading into the 2013 draft vs the trade value of unprotected draft picks heading into the 2014 draft, it's a no-contest. Cleary 2014 1sts were more valuable. There were thought to be several potential stars. So sure, you can stack up McCollum/Giannis/Gobert against Wiggins/Embiid/Parker and retroactively decide both drafts were comparable, but if we're talking about the value of those picks pre-draft, you have to consider the perception of the draft and the widespread consensus of how "hit and miss" it can be. It's not a coincidence that the best players from 2013 are a smattering of unpredictable guys taken outside the top 5, while three of the best players from 2014 were taken in the top 3.
It's my understanding that 2017 is comparable to 2014. Experts seem to have a handle on which of these guys could be stars. Nobody is labelling it a "crap shoot". There are several guys up top that are widely expected to make an impact. Also, while many fans have anointed Fultz as the best player, there's no real consensus right now on who the #1 pick will be. There are multiple candidates and they all have legitimate star potential. So think about this... this is an exceptional draft. That means a top pick in this draft has more value than a typical draft. Additionally, you can acquire that pick without impacting the Nets. The Nets are currently the worst team in the league by 6 games. The Bucks had the worst record heading into the 2014 trade deadline, but this Nets pick is more valuable than that 2014 Bucks pick, because trading for it will not sabotage the pick. Theoretically had you traded away a star at the 2014 trade deadline for the Bucks pick, you were now running the risk of the Bucks winning a bunch of games over the second half of the season and impacting the odds of the pick winning the lotto. That's not a concern with the 2017 Nets pick. That means this Nets pick is even more valuable than a traditional top pick in a great draft. I'm having a hard time finding a situation similar to this. It's a historically valuable trade asset.
Of course, this is all based on pre-lotto value. Sure, the Nets could win games over the second half. Sure, even if they finish with the worst record, that pick could still end up 4th (still an outstanding prospect). But if we're talking about the value of an unprotected draft pick heading into the trade deadline, you really can't get more valuable.
Here's the other thing. All-star players don't typically get traded for assets like this. There seems to be this idea that you need to give up multiple incredible draft assets to acquire an all-star. SOme fans are under the impression, for instance, that Boston would need to give up Jaylen Brown, Jae Crowder and BOTH Nets picks for a non-Superstar like Jimmy Butler. I think I know why this is, but first let's just take a quick-glance look at what some previous all-stars went for at the trade deadline.
2015 - Boston acquires Isaiah Thomas for Marcus Thornton and a late 1st rounder. If we're looking at the most recent deadline star acquisition, perhaps we should have our eyes on this as setting the value of acquiring a star.
2011 - The Melo trade. There were a lot of moving parts here. It wasn't just Melo. The Knicks also got Billups, Brewer and others and gave up Felton, Gallinari, Chandler, Mozgov, Koufas, a future mid 1st (became Saric) and the option to swap picks in 2016. Melo was a bigger star than Butler is. This would be like Boston getting Butler and others for a pu-pu platter including Crowder, Smart and some non-Brooklyn 1sts. That's the conventional return for a star player. It's always a little bit of this and a little bit of that.
2008 - Pau Gasol to the Lakers for expiring contracts, the rights to Marc Gasol, a 2008 pick that became Donte Greene and a 2010 pick that became Greivis Vasquez. Again, I'd say Pau was a significantly better player than Jimmy Butler and yet the return was a pu-pu platter of assets. It should be noted that nobody had any real expectations of Marc Gasol at the time. He was the equivillent of us trading Ante Zizic. This would be like us giving up expiring contracts, Zizic, and a couple non Brooklyn picks for Butler. That's conventional return for a star player.
2004 - Rasheed Wallace for a 2004 1st rounder (#17 pick became Josh Smith) and filler. It wasn't even a lottery pick. And yeah, I get that Josh Smith exceeded expectations and became a star, but again - a Cousins-esque knucklehead of a star was acquired for a pick that wasn't even in the lottery. That's conventional return for a star player.
You can go back further and find other trade deadline star trades, but they were all basically star-for-star deals. Mutumbo traded for Kukuc. Gary Payton traded for Ray Allen.
The only stand-out deadline day deal that you could say is comparable with the ridiculous "both Brooklyn picks + Jaylen + Jae for Butler" ideas was the Deron Williams deal... and that Deron Williams deal is widely regarded as one of the worst in recent history by a running joke of a franchise. Nets got Williams. Jazz got Derrick Favors, Devin Harris, the Nets 2011 1st (which ended up Top 3 despite the Deron addition and the Nets finishing with the 5th worst record), and a late 2013 1st.
Are people using the oft-ridiculed Williams trade as a barometer for what someone like Butler should be worth? Why would we we try to replicate a disastrous trade? I'm throwing it out. That trade was ridiculous. Even if I didn't throw it out, a equivalent trade would be Butler for Jaylen Brown (in replace of Favors), a pick projected 5-8, and a future late 1st.
There's been other semi-recent star trades that are notable, but didn't happen at the trade deadline. Chris Paul was moved for Eric Gordon and a future late lotto pick (#10 - Austin Rivers in 2012). Chris Paul was a legitimate superstar at the time. He was a significantly better player than Jimmy BUtler. But even if we are going to pretend Butler is on that level, the equivalent would be trading Avery Bradley (in replace of Gordon) and a future late lotto pick.
Dwight Howard was considered a superstar at the time he was traded to the Lakers. The Lakers gave up another star big man to acquire him (Andrew Bynum). We could leave it at that, but a lot of folks like to harp on the pu-pu platter of assets the Magic got in return for giving up Dwight (multiple teams were involved). They got some players and a smattering of 1sts (pretty much all had protections on them). In retrospect people have commented favorably on the return Orlando got. That's fine. But still, none of those picks were the heavy favorite to land #1 in a loaded draft.
We all know KG was acquired for a package built around a great young prospect (Big Al). I guess you could pick your favorite Celtic prospect to make an equivalent package. Smart? Brown? Both? Whatever. Neither Big Al or any of those prospects carry the trade value of this Brooklyn pick.
We know we acquired an aging Ray Allen for a #5 pick, but that draft was only seen as two players deep.
It just doesn't happen. When teams are looking to dump their stars, they just don't get the kind of return people are saying Boston needs to give up here. They get a collection of players and late 1sts. They maybe get a lotto pick. They maybe get a solid prospect without superstar potential. They never get a superstar prospect or a pick that is likely to become a superstar prospect. It just doesn't happen. There's really only one example of it happening... and it's not fair to hold that up as the market-defining trade.
I'm talkin about Kevin Love for Andrew Wiggins...
That was an exceptional situation. It doesn't happen under normal circumstances. That happened because the god of the NBA (LeBron James) was willing to sign with a team as a free agent contingent on them acquiring Kevin Love. I blame this trade for these "2017 Brooklyn 1st for Butler" trade ideas. You're missing the context of that Kevin Love trade when you bring that up. There's no way in hell Cleveland gives up Andrew Wiggins for Kevin Love without the LeBron factor. It was an unprecedented trade that was nothing like the all-star acquisitions of the past. I said this Summer that I'd be ok with adding Jimmy Butler for a crazytown overpay, but only if it was mandated by Kevin Durant as a precursor to him signing with us. That was the only way an overpay for Butler made sense - if it assured us we'd sign Durant. But of course, you do pretty much ANY deal for Butler if it guaranteed you Durant. The same way the Cavs would have done basically any deal to ensure LeBron was happy (despite the order of how those events went down, I'm pretty sure trading for Love was part of LeBron's decision).
Ignore that Wiggins/love trade. It set a bad precedent that makes jack sense without the LeBron signing. That's not what all-stars are worth. Just based on the value of this Brooklyn pick and it's potential to become a "transcendent" player, in conjunction with what we've seen stars go for in the past (player pu-pu platters or late/protected 1sts), that pick alone is a massive overpay for 27 year old non-Superstar (that his team already decided isn't worth building around) like Jimmy Butler. I think it's crazy that some people think it's a good idea to not only give up that pick but also the 2018 Brooklyn 1st + significant player assets. That's far too much for a guy who might not even move the needle.
Before I finish this rant, let me focus on that for a second. Seriously, even discounting out how I feel about the value of that Brooklyn pick, I'm legitimately not sure Butler can move the needle. I've jokingly referred to Butler as "Premium Brand Ricky Davis", but I really mean this. Defensively, I'm not sure he provides much of an upgrade over Jae Crowder. Offensively, he undoubtedly can create his shot better than Jae, but is that really something we need? Jae has been exceptionally efficient this season. He's arguably the 3rd best three point shooter in the league this year. He's close to the 50/40/90 club. One of the 6 most efficient shooters in the league. Yes, he does that as the 4th option on the Celtics. Yes, Butler would immediately be our 2nd option on offense, but in light of what Thomas has been doing for this team offensively, do we need that? You're basically saying we need Butler to have another go-to scorer at the end of games. But considering Thomas has been otherworldly and arguably the best late game "go-to" scorer in the league this season (while doing it efficiently), what's the benefit of cutting Thomas late-game scoring efforts in half to put the ball in Butler's hands (who may or may not be able to score as efficiently)? Scoring isn't our issue this season. Thomas is surrounded by highly efficient shooters and it's working. I seriously don't think cutting back Thomas' role to add another go-to scorer is going to do much for us. At least a hypothetical DeMarcus Cousins trade makes some sense considering the needs of this team. I think we'd gain far more by having a star big than we'd ever get by swapping Jae or Bradley for Butler.
I guess the bottom line is that if I were forced to make a trade, I'd far rather acquire Carmelo Anthony on a bargain than give up a single Brooklyn pick for Jimmy Butler.