Hard to give advice on a make/model, but whatever you go look at, if it's possible, have them run it through a burn cycle for you. Sit there and observe (do you see, hear, smell anything that puts a red flag up). Make sure it all works. I don't know if its possible to overfire a pellet stove as you can a wood stove, but check for cracks and busted weld points anyway. To check its age, there should be a manufacture date stamped on the back somewhere. Use the internet to research it and make sure you can still buy parts. We scored our basement stove on craigslist this way. 2010 Heatilator PS35 - original owner maintained it well. It was too small for his house, so he was selling it. I took the thing apart and looked at the blowers, wiring, etc - the thing was spotless so the guy either kept it this way all the time, or cared enough to clean it up nice to sell it. To me, that spoke about the seller's character, but he still ran it through a cycle for me, which spoke even more. That's my long answer. My short answer is, look for Harmans if you have the $.