Re buying one, my advice is,"Don't bother!" The bulb/element seems to be especially vulnerable, judging by stories about these things, but it is not a case of just buying a bulb and popping it into a socket. It is not something the owner can do...unless, I suppose, you are an electrical technician of some sort.
I bought one and it came with part of the plastic base weighing about three ounces broken through. Did I just have to send that back? Oh, no! I had to repack the entire thing and send it all. Fair enough, I got a replacement and was just getting used to - and enjoying - cooking with it, when the bulb/element blew. I decided to return it and ask for my money back. Clearly, these things are of low quality for one reason or another, as the price nowadays would suggest.
Of course, you will almost certainly get someone else here replying that they are the finest thing since sliced bread. If you're a gamblin' guy/gal, go for it, but my advice if you do is...note how it all fits in with the packaging as you UNpack it and don't throw the packaging away!
I finally invested in a Remoska, a much sturdier and more reliable device. They're quite a bit more expensive, but well worth it, I feel.