The thing about all these trades is I'm fairly confident that Boston will not be able to put together a better package than Philadelphia because Philly has multiple high value players AND multiple high value picks. So say Cousins does in fact come on the market, Boston can't top a package of Okafor, LA 1st, Philly 1st (just as an example). No amount of future unknown draft picks is going to overcome that sort of offer. In fact, Boston can't top that package for any player. Now Philly may not be in on every trade and may not put that sort of offer out there, but there is no way Boston can put together a better offer than Philly for any player that Philly actually wants and that would come on the market during the season. None at all.
You ignore the fact that pretty much no quality player would want to go there due to their culture of losing. Their reputation is totally soured around the league. Look at the Love situation - he had quite a bit of "say" where he went, and the same will hold of other stars on expiring or soon to be expiring deals. And even non-expiring deals, like Cousins, will be hard for them to attract, because no player in their right mind wants to go to Philly right now.
These are great points, and you're both right to an extent. Philly can trump and offer, but their position is weakened by the fact that no star would want to play there.
It wouldn't be impossible or unprecedented, though, for Philly to orchestrate a whole package of acquisitions in order to have a star player consent to a trade and/or resign with them. No star wants to go team up with the rookies and nobodies in Philly, but suppose they brought in some foundational guys first, or they worked an angle with a few stars simultaneously.
You can say no star will play there, but is a guy like Cousins really going to sit out and not play and not collect a pay check. I don't think so. Cousins also has made it clear he wants to play next to a defensive whiz, Philly just happens to have one of those, who wouldn't be a part of that trade (since Sacto has its defensive guy and would want Okafor to replace cousins and who would be redundant with Cousins so Philly wouldn't need him).
I get a star probably won't sign as a free agent in Philly as currently constructed, but trades are vastly different. Very few players actually have the clout to not report (and even fewer have no trade clauses).
And for as bad as Philly is right now, they are a gigantic market, on the East Coast, with a long and strong history for winning. This isn't the Kings.
My opinion is that while you are correct that few have the clout to not report, the reason this isn't more common is that trades don't get completed if the player has no interest in the final destination. Thus, a lot of trades get squashed behind closed doors well before they would have been completed.
While I know your idea of Philly being able to outbid us applies to other players, I honestly don't think in this case Cousins even gets traded. I think Sacramento grabs the last playoff spot in the west and that is enough to appease him.
As to having a history of winning, the last time they had a really good team a lot of the star players now were in diapers. I don't think their history matters to younger players anymore than ours does.
I just used Cousins as an example, because a lot of people think COusins is going to be traded. Cousins also is a guy with a lot of years left so whether he really wants to be there is less of a factor (since you won't have to re-sign him any time soon, and he can't just hold out for a couple of months and be a free agent).
I don't think the history matters as much to the players, but it does to the owner, the city, etc. Philly will pay for a winner, because they always pay for winners. And I know they have new ownership, but they seem like the type that would pay for a winner.
Philly also has enough assets that they can get better in trades and still have the assets to trump our offer. I mean just adding Stauskas and the vet PF's in a salary dump, shows they are making moves in the positive direction.