I believe the Thompson's make a good deal of cash on endorsements (Nike) and their own lacrosse business. The amount they make from actually playing the game is just a nice bonus for the exposure they get. I beleive Rob Panell became the second player to ever ink a $1,000,000 in endorsements, I wouldn't be surprised if Lyle was the third. It seems to me like his entourage is living a pretty good life and they are all employed by TB Lax.
During my time at UA, we got very little monetary support from alums (Though the moral support was always amazing). It takes a very wealthy person to be able to put up the serious bucks we are talking about here, and since UA has only been D1 for 18ish years, the OLDEST UA lax alums are only in their late 30's. They are more concerned with saving for their kid's college than building facilities at UA.
But Hey, A guy can dream