So, just out of curiosity, I was looking at the tax spending from every NBA team over the last 10 years. Some spend, some don't. Celtics are a bit above average, I'd say, but here are a few teams I thought were most interesting...
https://www.spotrac.com/nba/cba/tax/Celtics: ownership spent during the KG years, I'll give them that. But they never went as deep as they could have, I don't think, when compared to a few other teams during that time (Lakers, Mavs, Knicks, even the Cavs). Most they spent was about 15 mil, every other year under 10. Good? Eh... above average. Def could've spent more to keep up with the big dogs. They spend more in 2010 and they very well may have banner 18 and beat LA.
Since KG/Paul left, team has only gone into the tax once, and not by much. 3.4mil. Team has been rebuilding, fine. Not now. Time to open up that wallet, Wyc!
Knicks: I always thought Dolan was a cheap ass who didn't spend based on his rep, and since 2015, he kinda has been, but before that? Surprisingly, they really spent their faces off. They've paid the most luxury tax of any team over the past 10 years. Color me shocked. Dolan must truly be insufferable to deal with or flat out incompetent, maybe both, if he's willing to spend and still can't get a competent team on the floor.
Lakers: here's an interesting tidbit: The Lakers went on an awful run in the 2010s after Kobe retired, but it specifically coincided with the passing of Jerry Buss in 2013. They haven't spent into the tax ONCE since then. Jeanie looks to be quite the tight wad; her dad was the real fan. Regardless, they still won a title cause LA is LA and Lebron is Lebron.
Mavs: Cuban has, I think, a well deserved rep as being a fan-friendly owner that he built up during the Dirk years. To his credit, he spent his ass off during those years. But since 2012? Not a single year in the tax. I won't hammer him too hard, though, Dallas is 3rd in spending the last 10 years, so he really went all in with Dirk & co. He'll undoubtedly soon have to do the same with Luka.
Warriors: 2 of their 3 titles were won without going into the tax. Shows how good their drafting was! They've only gone into the tax 3 years in the last 10. Sounds pretty measly, huh? Thing is, they spent BIG money those years. Enough to put them at #8 in the highest spenders list. That said, feel like they should be spending more. That team is worth a ton.
Anyway, there's some other interesting teams to look at, but I'll stop there. I don't know how much these guys can afford to spend, but ultimately, just gut feeling a lot of these owners could probably spend much more than they do, but it is what it is. This is a business first for like, all of them. The ultimate goal is to make a profit, and a big one at that, otherwise they'd do something else with their money.