the price depends on the market.. if you are out in the middle of no where, it's not a $100 bike. but you live in a California college town where any working bike in good condition can be sold for $100.. I dont think you could low ball too much

go take a look at it and if it looks good, ask if they will take 80, but buy it for 100 if you like it and it doesnt need anything besides the tires pumped up