You misspelt Donor. How about put in a new VIP rank, so people have exclusive features and some cool commands like ::teleto, ::skiller , maybe gets some skiller skills that you can't get, VIP gear, Increased xp gained per mob, maybe keep more items when you get killed than an ordinary player.
The extra money gained from stalls is a great Idea! Maybe the VIP rank could be better than the Donor rank, therefore costing more.