I use my mega quilter for free motion quilting. You set the stitch length to zero, cover the feed dogs and set the presser foot pressure to zero. I bought a open toe FMQ foot and modified it according to directions from Leah Day (google for her website). The modification keeps the foot from hopping up and down. This makes it a little easier to FMQ.
A few have recently sold on ebay for $500. That is for the machine and table, no frame.
I've had mine for about 7 years. You do have to adjust the tension based on thread and fabric being used. It also is a bit more involved to thread it than threading most modern machines.