I have seen this on other on-line sites that have supporting memberships. Basically you charge a one time $100 to $150 and the person becomes a "permanent" supporting member. Some places only offer a few of these at a time (20 to 50). It is purely optional and people can choose to be the supporting member for the normal annual fee, or pay the larger fee and be a permanent (supporting) member.

Maybe other perks of being a permanent member would be:
-Get first chance to be a Moderator is a position become available
-Another icon in the profile (similar to the star, etc.)
-Maybe get a small bit of web space on the site for picture hosting of all your gear or a picture of your band or something, to make it easier to post the photos in the forums
-maybe other ideas that I can't think of right now???

Just a suggestion for increased revenue over a short period of time.

-KB