Gentlemen,
Again this all depends on the amount of money you are spending for the used items, I would not purchase a used Legacy Shay if I could pick one up at Patrick's trains for just a little more money... snip...
I picked up the P. Bunyan Legacy 2-truck Shay for $380 a couple of weeks ago on eBay, runs like a top. The only thing I had to do is glue the headlight lens that got dislodged in shipping. I could have had it for $799 at Pat's Trains, but I have other things to do with that extra $400. New engines are a lot like new cars. Yes, you get a warranty, and it's brand new. However, you pay dearly for that "new train smell".