I tend to buy and sell more than my fair share of bikes. Ask anyone that knows me There's no shortage of used bikes avialable. So, unless it's an uncommon model, the asking price makes a big difference to me (not that I ever pay asking price). If the asking price is 10-15% more than I'm willing to pay, I'll just look for the next one. Not that negoiting more than 10-15% is impossible, but why bother? If it's an uncommon bike, there's probably few around and also few buyers around (if there were lots of buyers it wouldn't be an uncommon bike, right?) and there is usually more room to negotiate. It makes no difference to me if someone asks $10k for a bike I feel is worth $5k, I just wouldn't call. The market is self correcting anyways, if it sells great...if not you may need to drop the price.