5' tall, 30" wide, 24" depth.
Assuming you have the tools needed to make it easy (and worth your time), probably $70 in Wood, Screen, and Screws. Stain and Poly are a bit extra, but if you are doing multiple cages, that gets spread out.
Clearly that does not include lights, plants, or the drainage stand, although there is not much to that.
HTH,
Bobby