All teams in all leagues except apparently the Cowboys (lol) have extra deals with players whether in writing or understood agreements under the table. The NBA's unique, a single player can generate multiples yearly of whatever they signed for off merch & tickets, only ones who thought players only see that number for the year on Spotrac are the nerds already on Spotrac. LeBron's added hundreds of millions annually to every team he's ever played for, you think he's only seen 50 million of it a year?
Toronto was looking for sponsors to keep Kawhi, there's details in a book that the Nets were buying townhouses for the players IG smuts in the KD era. People thought Dennis was crazy when that list of demands to the Lakers leaked out.....no, you were just getting a peak behind the curtain and didn't understand what you were seeing. Lakers leaked that because they wanted to get ahead of ending talks because the nikka wanted a jet and ownership stake.
It's common, what isn't is getting caught. Luckily for them they have the softest commissioner in sports, a couple picks and a fine. But Ballmer's already said fukk picks and he's the richest owner in the sport, I'm not sure there's much else you can do.