I just sold one for $800 WITH a stitch regulator. I used it for over a year and really liked it. (My SIL used for 3 years) The only problem I had was getting the tension set, but once I did, no problems. It really needs to be cleaned yearly. The stitch regulator is over $500.
The frame I had was a B-Line that would make to 10ft. Check out and see what the cost for the frame and machine cost new and then decide if it's a good buy. Be sure and try it out and see how smooth it sews.