Buy Vip Status - Get xp at a faster rate
Donate for XP:
ie. Donate $1 get 500points. 5$ = 3k points, etc. Money used to support tournaments and get prizes for wikia competitions.
I don't know how viable that is as people could just donate for XP and get items/pets. But I would be willing to setup some items for the shops =]
Also maybe a VIP package or something? Donate $5 get VIP status and 1k XP pts.
Again, just a thought =p