I bought a computer & an ereader about two months ago - I think that I may have mentioned both here, possibly without being too specific.
The computer was DOA out of the three boxes (no bubble wrap) that the seller had jammed it into - I escalated to eBay and got my money back & a prepaid shipping label, even though the auction was listed as "no returns".
The reader worked when it came in, worked after updating over the USB cable connection to the computer, but updated again the next morning over wireless, and bricked itself - I'm out roughly $20 as a reminder that the particular make & model (Kobo 2gb with a control pad in the lower right hand corner - several different numbers in various colors) has to be kept off the wireless as it will immediately install an update and brick itself (that was the second one, it had just been long enough that I hadn't recognized it as the same one until I went into my eBay purchase history).
I ended up deciding that it wasn't the seller's fault...so I didn't file with eBay. But I have debated what to say if I get asked to review that particular device.
I got several months use out of the first one, so it was not a complete loss - the second one, I got to read for about 45 minutes before going to sleep after setting it up - but I've made a note not to buy any more Kobo with a square rubbery control pad in the lower right hand corner...as they aren't worth the trouble, much less the money. I just hope that I remember to check my notes when in pursuit of a "bargain"...