Hi Bev, the Consew 226 is a clone of the Singer 111w155, which is a truly heavy-duty industrial machine designed to do auto upholstery work. As I believe someone typed above, this machine can go through a lot. The Consew 226 is basically the same machine with reverse added as a feature. I don't know if I'd call them rare, I think it all depends on whether you live in an area with a lot of factories/manufacturing.
I don't have any direct experience with the Consew 226; I've recently acquired my first 111w155, the machine it was based on, but am still waiting for some parts to come in. But both of these are walking foot/compound feed machines, meaning that the presser foot, the feed dogs and even the needle bar all move together to help advance the fabric. From what I've read, these machines are well-suited to heavy work and not suited to thin fabric.
$1000 sounds a little crazy to me, but that may be because I only wait for bargains. I got my 111w155 for just $15, for example, though I'll probably spend another $200 in parts. Remember that the Consew you're looking at is probably hooked up to a clutch motor, so if you want to get a DC servo motor, which will enable you to go at very slow speeds, you can expect to spend another $100 - $200.
If I got it into my head that I was going to spend four figures on a heavy-duty industrial, I'd probably buy one from Bob Kovar, who has a reputation for being the go-to guy for industrial and walking-foot machines. If I'm going to spend that kind of money I'd want to know there's someone I could call if there's a problem. He sells the Consew 206 (an updated version of the machine in your ad) for about $1300 and is based in Ohio, his website is here:
http://tolindsewmach.com/consew-206rb.html
good luck with it,