I would search around on classifieds and craigslist. I have a Janome 1600. I bought a Grace frame from craigslist for $200, with a stylis, bungee clamps, and the leaders all included. I had to look around at different cities in my area and drove a little bit to get it -- but it became a day trip for us and was fun (after we got it to FIT in the car). :)
The only thing I had to buy to make it work for me was the speed control hand button, which I found for $50 at allbrands.com
It definitely makes quilting easier and more fun. One thing I don't like about mine is that it isn't big enough for a King size (but how many of those am I really going to make?). Also, particularly when I get to the end of the quilt, I can only quilt a few inches at a time because of the bulk (limited throat space). But, it's bearable. As long as I do the meandering (rather than trying a pantograph), it's just fine...and I don't have to unload and reload (like vnengels mentioned).
You might also want to check some LQS for some used lower cost frames that people have traded in. But keep checking craiglist!