Depends on the condition, if it's in-hand, whether if it's only tested or second-hand. I suppose you're getting one in-hand so a only tested one ~$400-$700, a second-hand (good condition(only used for 1-3 months)) ~$350-$600, and a bad second hand( used for more than 5 months) ~$250-$450......Note: the above is just my opinion......btw people with in-hand bfl products might be a little crazy on the price, I've see a 5gh/s jalapeño for $2500(just saying)......