Staff Question

If Paul Allen does not care about money, which I am gathering from NO's exit interview, what's stopping this team or any team from just paying ridiculous amounts of money to retired players, or staff to improve players.

For example why not pay the best defensive minded retired players in recent history to be on staff and work with our boys, the best post players ever to come in a teach Vonleh, or the best defensive minds ever to come in and teach our guys how to play amazing defense.

Can't Paul Allen just pay like a bazillion dollars to whoever the best defensive coach ever is to come in a make us the best defensive team ever? Is there a cap to what you can pay staff?