A lot of times clubs or organizations will offer different levels of memberships, like bronze($10?), silver($50?), & gold($100?). You could also offer corporate level memberships ($200?) for those companies that wish to contribute (like Manhattan Optimists).
Besides hopefully seeing D1 wrestling in the future, what else is in it for those who donate? I'm thinking along the lines of free tickets, hosting camps, or maybe put them on the mailing list for a monthly newsletter (you could list new sponsors & upcoming events in this). Sometimes undertakings like this animal work better if committees are formed & assigned to specific duties such as the newsletter. Just a few thoughts that will hopefully help keep this great idea flying!