Assuming the seller built/assembled this bike... the guy could have easily spent $2500 on the bike and he probably wants 100% return on his investment. The frame alone could be upwards of $1500, plus ~$250 for the paint job, another ~$80 if he anodized the hubs himself (i.e. he didn't buy them that color), plus an expensive saddle, crankset, pedals, hubs, et cetera. It all adds up.