I had a king size Gracie frame and it wasn't much smaller than my HQ frame. I paid $1,000 for just the frame, and that was several years ago.
Mine was pretty easy to assemble/dissemble, adjust size (it could be set up three different widths). I sealed all the wood pieces before I assembled as they came raw wood, but that is not required.
Mine came with a metal carriage, and also had plastic rails, but they could be replaced with stainless steel bars.
the good part about buying one used, you don't have to deal with the full assembly
