Personally, I wouldn't go for a 3TB drive, especially a used one. It's best that you get a 2TB 7200rpm instead, and if you really want more than 2TB, you could go for either a 2TB 7200rpm x 1TB 7200rpm, or a 2TB 7200rpm x 2TB 7200rpm. It will cost you a bit more for one 2TB drive, but at least it guarantees longer usage of the hard drive which is definitely worth it. Overall, if you're willing to do the gamble, you could go for the 3TB, or if you want to play it safe, go for something else.