Hello. New member here (but have poked around on threads, reading and researching), and also new to pellet stoves. We are in the market for a used one for our approx. 2000 sq.ft. home (with propane furnace). We have an opportunity to buy a Quad Mt. Vernon for $500. It is a 2006 model, works well according to the seller. Just wondering if that is a good buy, especially considering its age. Not sure if it's the AE or not. Also, any input on red flags we should be looking for?