Try craigslist.com. They should have a local one for your area. Generally, there are alot of good deals on it. I found my Gixxer there and got a really really good deal. If you PM me where you are, I can find a craigslist for your area.
If you are anywhere near Orlando, try
http://orlando.craigslist.org Make sure you are somewhat vague in your search criteria. On the listing of my bike, I had to search "gsx-r", if I did "Suzuki GSXR" or "Suzuki GSX-R" it would not come up as the guy did not put "Suzuki" anywhere in the listing.
PM me and perhaps I can help you out.