I Never buy used
Why buy something that's most probably been broken once already. No open box, floor model, demo unit can be offered(free?) for any price to make me want to clean up behind another tech, when it breaks again and I have to fix it. If the seller doesn't have one, in the box, factory sealed tape intact, I won't touch it. I often get offered units that are cheap but have a slight problem, DVD stuck in drive, OS corrupted and no back up or system disks available, or a sound card quit. I have no market for these turned around units when they should get donated.