Seems like more are non-running than not. That can work for you, or against you, you just have to be careful and pay close attention - especially to the pictures. I do have to agree with TheBrushSlasher, that some of the sellers are
way off base and asking ridiculous prices for something that looks like it fell off the back of a garbage truck, but some are just looking to move inventory. I've gotten some very good deals (like a solid SXL for $45 shipped), and some saws that had severe issues that were sold as runners.
Most of the sellers don't want a black mark on their reviews though, so they'll do something to work with you if you complain to them, even if begrudgingly. I had what I believe was a 2-10 that was sold to me as a 7-10. I griped to the guy, who got and attitude about it, but offered to refund me. I had already put money and effort into it to get it running, so I was like dude, just refund me shipping (he did) and then I sold it off for what it was to someone who was thrilled with it and I about broke even (maybe came out a few dollars ahead).
You guys are spot on with Stihl, people seem to think they're made of platinum or something. Like here's this roached out 029 I found in a barn with destroyed piston, rusted out muffler, missing mag/cover, no bar/chain, and covered in rat droppings. Starting bid; $160.
I guess you could argue that you could part out what's left and make a little something, but...