A warranty can be a beautiful thing. I like my HDDs to come with one.
I have a Fireball LCT, it's a noisy pile, but it still runs perfectly(a speculation, as I haven't booted the old system in 9mos). The HDD you get will be unique. It could arrive DOA, or it could last decades. You pays your money and you takes your chances. I personally, wouldn't buy a used HDD. But if it's only something like $20, then whatever, get it and.....nah I still wouldn't do it.