I bought a used Kobo Glo on Ebay for US $60 about 6 months ago. With Ebay there's always some risk but overall I've had very good luck with them so far. The Glo was just fine. It didn't come in a new box or with any accessories but that was stated in the description so I have no complaint. I can't tell in any way that the device itself isn't a new one.
By the way that was my second attempt to buy a Kobo Glo. About a month before that I bought one on Ebay for $40 and the guy sent me a Kobo Mini. I emailed him about it and got no reply. I waited a week and still no reply so I emailed him again. After a few more days I was getting ready to contact Ebay and he finally answered. He explained he'd been out of town and he didn't know the various models and thought this was a Glo and he'd just issued a refund and I could keep the Mini. I checked and sure enough my refund was in Paypal. So even when it goes wrong it can be alright.
By the way, the Mini was also in like new shape.
Barry