That is a difficult question at time because it really depends on the person selling and what someone thinks or feels it may be worth. Unlike older series the newer like the 10's and 20's nvidia binned the better gpu's for themselves. So what is left to the others like ASUS and EVGA and MSI, is to make the most of the lesser quality and apply better cooling solutions to boost performance to what nvidia might have or better. I recently just sold 2x GTX 980ti lightnings, which are really good for $400 and the price of shipping. I felt they were worth more because of the overclock capability they had, and since they were 900 series they probably had better units to match the cooling they had. Sort of hard to put a price point on it but I don't really expect anything over $450 being on the really nice side. But in reality I might be putting a price of maybe $375 or less. How much do you feel like you should get for them, if your expectations are high you will be disappointed every time. People go used for deals, if you go to high people will look elsewhere or just spend a little get one new.