If you really want to go "on the cheap" go to the Lowe's or Home Depot, select a sheet of plywood with one smooth side, have it cut to width on their panel saw. Then sashay over to the building gadgets area and purchase a set of the new-fangled plastic sawhorses. These adjust up and down, and might be tall enough to keep your backache to a low roar. Just sand the edges of the plywood, give it a couple coats of paint, and you couldn't get much cheaper than that.
Happy quilting!