Sham Sports shows us at $53.8 million, but I think that is without Baynes which brings us to $55 million. That is also without Mills so you can see we are then up to about $59 million with a cap of about $63. Boris will clearly command more than Mills, and you can see why the math starts to put us at $65 million+ after signing Boris. Spurs won't likely run the payroll up near $70 million in my opinion unless they can get a big fish like Gasol in free agency. Otherwise I think our dollar and roster size limitations will control.
I've seen some indicating they would like to trade Daye, Ayres, and possibly Belli. Belli averaged 11 PPG in the regular reason and hit some big shots in the playoffs. I don't see teams lining up for the other two, but I guess stranger things have happened. Certainly if we added a high quality big I'd think offloading Ayres would be a top priority.
Let's keep in mind though that those players were in year one of learning our system, and year 2 may be better.