If it is a fire sale, because of an actual fire - then you might be taking a chance.
If they are just dumping those on the market, and asking a price that you like, then jump on it.
Maybe it's just a good deal... Nice size for a hard drive, I think.
Buy one that is listed as "new".
If you are concerned about warranty,
Buy two, and use one - keep one in the box as a spare.
...It's just a hard drive...