Your salary projections seem fair to me, but I think your overall payroll expectations are off.
Portland already has $137m in committed salary for 2018 and CLE has $132. OKC, LAC, and MIL all have $110-$112m. What might LAC look like when Paul and Griffin opt out and re-sign for bigger deals?
I think $125m might become the new normal and few teams trying to spend to become contenders will hit $150m in the next few years.
With the $50m-60m-ish cap we had for the last 10 years, we constantly saw teams in the $80m-$90m range. Though there were fewer after the most recent luxury tax rules were implemented, there were still like 2-4 per year, right?.
$60m cap, $80m-$85m payroll is 133%-142% of the cap. 2018 and 2019 salary cap are projected to be $102-$108m. Luxury tax is usally 120% of the salary cap so will be about $130m, and if we apply the same percentages we've seen teams go over in the past, that gets you in the $140m+ range, $150m+ on the higher side.
With where some teams are already, I wouldn't be surprised to see teams start getting in that $140m-$150m range over the next few years.
Of course part of this assumes they adjust the current luxury tax rules to the higher salary cap. Doesn't make sense (to me at least) to keep the same fixed dollar amount luxury tax penalty thresholds with the much higher cap. I guess we'll see if this is addressed in the new CBA they're currently negotiating. Even if it's not, the top threshold is currently $20m over the luxury tax line (which could be $130m), so I still think we'll see a few teams get to around, if not right under $150m. Might not sound so outrageous in a couple of years.