I disagree with BBM. I've willing sold bikes for less than the rather arbitrary, in my opinion, $100 mininum profit margin, just to make a sale and a satisfied customer. Tires for that bike should run you no more than $20. If you can't get $150 for a Sprint, maybe you can sell it for $120 and double your money -- what's wrong with that? Even at $90 sale price nets you half again what you put into it ($40 purchase plus $20 pair of tires).