This doesn't answer your question in any meaningful way, but why wouldn't you be able to buy as many as your donation qualifies you for? I.e. A $3,500 donation you can buy 2 club level seats, 3 scoreboard seats, 4 chair backs, 7 section D, etc. you could buy 20 or so at the lowest level.
In practice, though, I understand you're limited to the number of tickets you bought last year unless you requested an exception.