There is a great thread over in the husbandry section:
http://www.cornsnakes.com/forums/showthread.php?t=6027
It really helped me build my own, though you still need to have access to a table saw at the minimum, or at least get the guys at Home Depot (or wherever you go) to cut everything to size for you.
If you would want to buy one of those racks, I would guess they would cost
at least $200. Melamine is expensive and those are huge racks he has there.
The rack I recently built was a shoebox rack that holds 25 boxes. It measures approx (I'm trying to remember off the top of my head here) 4' long x 1.5' deep x 3' high. Including the boxes and heat tape, it cost me a little under $100, but I used MDF rather than melamine on mine. MDF is basically melamine without the white protective covering.