If you can get over your qualms about BD, if you want the most bike for your buck, they have a sister site bikeisland.com. They sell parts through that site as well as a "scratch and dent" bike section. Selection/size/year/color are limited as well but if you find something that works, it's usually a $600-$700 BD bike for $500. If you look at the description for the bikes, it's mostly described as scuffs or scratches; most of them are not dents. I have bought 2 bikes through bikeisland and I would describe the scratches/scruffs as something I would expect after owning the bike a couple months. Sometimes I'm not even sure I see all of the scuffs/scratches they mention; it could just be a standard entry that they have or this could be their venue to sell last years models without decimating this years models sales.
If this fits you, this would be a lot of bike for $500
http://bikeisland.com/cgi-bin/BKTK_S...ls&ProdID=2218