Just so you know, there's a big difference between 'secondhand'/'pre-owned'/'used', and 'refurbished'. "Used" means you are buying it directly from someone (whether a face-to-face sale or buying it used from a store) who may or may not have taken care of it, may or may not have bought it from someone else who may or may not have taken care of it (you see where this is going?)... Even if the store selling it claims to have 'refurbished' it in-house, it is still a gamble, because all they usually do is clean it, give it a once-over to make sure it works, and slap a price tag on it..
On the other hand, FACTORY REFURBISHED means it has been tested, inspected, cleaned, aligned, parts replaced, and meets the same factory operating standards as a new unit. In a lot of cases, a refurb unit is in better working condition (albeit in a lightly worn shell) than a brand new unit off the robotic assembly line with the 1 of 50 QC check, because it has been fully tweaked by hand.