Mike, can you make the ebay link something other than an underline? Seriously, like a slightly diff-colored highlight? Of course the reason most people click is because they think it's a link that might be interesting, so I bet identifying it as 'ebay' means profits would drop.
Otherwise, keep it simple. If there's a way for paying members NOT to have ebay links and various ads, and maybe semi-uncensored signatures (no real profanity, but political, religious, and other unsavory references are OK) and perhaps an email account (since who gives a **** about PM space, really?) then there are a number of people who would pay $20-30 to support the site with a few minor personal benefits added. Let the rest of the folks continue on with ebay links and banners, keep their avatars, etc.... Maybe payers can have animated avatars, others can't.
OOOHHH I GOT IT!! You want to use the smileys? Maybe an EXPANDED smiley selection? heh heh. Cost ya $20 a year.
I still like the idea of initiating and widely publicizing a metro-phx lost and found -- just on lost cell-phones and pets alone you could probably make some dough once it gets well-known, say at $1 for a week-long listing. Finders don't have to pay to list, just losters.
I really like the idea of getting us access as a group to some subscription only services -- it may cost too much, but Baseball America prospect report, maybe ESPN.
How about having a menu-link thing in the food forum, offer to link to various restaurants -- esp take-outs -- for a small payment everytime someone either links, or maybe if they order.
How about setting up an E-Bay SELLING account -- maybe coordinate with a local ebay selling service to handle it -- I have a load of stuff I inherited that I should sell but I don't have the time or interest to jump the hoops -- but let's say ASFN somehow streamlines it or brokers it -- you can have a 10 or 20% commission, fine with me.
If you do have a members only forum, be real neat if you could get a couple local sports people to join or to host subforums -- maybe the stat guy from the DBacks, or maybe a Suns' trainer, or ideally, maybe offer rookie player blogs visible only to payers.