I believe usually they retail for $800, on sale for $599 or $699.
http://www.allbrands.com/products/1065
However, I purchased mine (very slightly used) from a private party for $400, and it came with a New Joy frame. It's worth it to put the word out that you're in the market for one. You might join the Yahoo group, I've seen them pop up for sale from time to time there. It's a great machine!