I have a site built up that has about 30,000 uniques every month, an active, enrolled community of about 1600 and has only been up for 11 months. Has a back end system for ads/banners that can be broken down by demographic and category.
Total development cost was around 50K because it was almost all farmed out.
Where should I start to shop this around? What should I start asking for?
Depending on what the monthly revenue is the first question to ask is why do you want to sell it? If your partners are bailing, couldn't you keep it and pay them their shares out of monthly revenues until they are out?
Check your partnership agreement (you did have a written agreement, right?) in it should be a clause to liquidate partners that want out. This is a pretty standard clause so that partnerships don't have liquidate every time a partner(s) want out and it allows for paying them off by a certain date and or monthly amount.