They sell well here, and you should be able to find a refurb quite easily for this reason. Various HTC models running Android would be my second choice.
What you should pay is relative to what the marketplace is asking, and what is reasonable to your situation. Look on ebay for a rough idea of what you might have to give up to get one of these. It will most certainly vary.
I have had great success in the past with refurbished notebook PC's(Acers). I would like to buy a smart Android(minimum 4.2OS) phone, with a good battery, 16GB memory, minimum 5MP camera, 2 GB, 3G network, good battery, USB port,Wi-fi, at least 1290 x 780 mp,
The guarantee would probably not affect me, since I'm in the states about 50 days a year(I live mostly in Thailand) and obviously a contract would not work for me.
So, how reliable and durable are smart phones and what should I pay and which manufacturers and models would be a good fit? I use the phone mostly for calls, texts, and watching football and baseball games on the Internet(I have Slingbox).