The Kings are not at the tax level, that is correct. They have 15 players under contract and 2 more with QOs. I don't think any deal is likely, I put this out as an idea more out of curiosity as to how everyone views Bagley's value relative to his contract, but I don't think SAC is going to do a trade where they end up with more players that they just have to cut. We aren't going to be able to "clean up our roster" by sending them players we don't want/need. An offer of a first round pick, even protected, and no players, may be of the most value to them.
Bagley makes around $11M and next year is a RFA at about $14M QO. This is right in the contract range of Robert Williams. Bagley is a year and a half younger. Both have shown promise, both have shown durability issues. Both have 3 seasons; Bagley has played 118 games, 52 starts, and 3,013 total minutes. Williams, 113 games, 13 starts, 1,656 total minutes.
I don't know if SAC has given up on Bagley. Williams, a comparable player at best, just got an extension. Bagley, on paper, should have more value based on his production, albeit on a fairly bad team (they were not that much worse than the Celtics last season though). If it is true that SAC is looking to move on, I would be interested in Bagley for a season, a season that is pretty much a bridge season anyway.