Taaaaaa daaaa your wish is my command! A real life Tier 6 omg
Basically, if you donate $100 USD, you get a Tier 6 Supportership, featuring the features of the earlier Tiers, (Blog, profile customization, etc) plus a 170x170 pixel avatar, 640x500 pixel profile picture, and a PM box that holds 1,200 PM's. (At least mine is 1,200)
EDIT: Mine is 2,000. lol.