Except for the up-front $10, the Somethingawful Forums do this. A few bucks for an avatar, a few bucks to change your avatar subtitle, etc.. It's all a la carte

Except for the up-front $10, the Somethingawful Forums do this. A few bucks for an avatar, a few bucks to change your avatar subtitle, etc.. It's all a la carte and all one-time purchases. They have the advantage, though, of having a huge community and thus a good deal of peer pressure incentive to get the extra bling. That, and your avatar is a "stupid newbie" picture until you buy your own.