Hi Helen! Glad to see an official Adorama presence here.
Unfortunately, if we're talking used equipment from Adorama, I have to put in a not-so-good story... a year or so, I was looking at Nikon Coolscan scanners and I found a used 4000ED at Adorama in EX+ condition for the too-good-to-be-true price of $199. I bought it immediately and when I received it, I found that it looked EX+ but that it did not work at all. In fact, when it turns on, the power light blinks quickly if there is a problem, and mine did. I did not know that but found it out with a little research.
Since it was so cheap (normally they go for ~$500 or so), I decided that rather than send it back to Adorama, I'd have Nikon take a look at it. Turns out that they have a flat fee for repairing them... plus pretty expensive shipping, plus tax... all told, I ended up spending another $325 to get it working. My great deal turned out to be only "OK" - I spent as much as anyone would spend for a used one but at least it was freshly cleaned, calibrated, and had a 6-month warranty.
I've bought other things from Adorama and been happy, and lenses are certainly much less sophisticated than scanners, but I can only assume that this scanner was not tested before it was put up for sale. (One other side note - it claimed to include all accessories, but I believe it originally came with a firewire PCI card. I have firewire on my motherboard so that's not a big deal, but worth noting.)
I don't doubt that Adorama would have given me my money back if I had tried, but it should not have been sold as EX+ at all considering that it was DOA. I would probably consider buying used from Adorama again but I'll always have this scanner in the back of my mind. (I will certainly still buy new stuff, and I may have the chance to visit the actual store in a couple weeks too!)