it depends on what kind of screen you use and framing.i estimated about 68ft of framing for a 2x2x4 aluminum cage depends on how you make the front.lowes sells the framing peices for 3.89$ each they were either 8-10ft.the framing i want is not painted its just brushed aluminum so at 8ft each x 8 peices =64ft. so it could cost about 32$ just for the framing ,the screening i can get a roll 36"x100' for about 70$ and that roll could be enough for 4 2x2x4 cages, im looking into where i can get the frame peices cheaper i believe i can find them in the 3.00$ range each.im gonna need about 34 of the to biuld 4 2x2x4 cages so im buying a box of them when i find them.
something to think about is if you only need 1 cage your better off just buying one already made ,but if your gonna need 4 or maybe even 6 it might save you some money but you gotta know what your doing because because screening the frames is one thing , biulding the frames ,screening them and putting it all together is alot different,i plan on making jigs for the 2 sizes of frames the 2x2 and the 2x4's that way each peice of frame i cut is the exact same length.
then when i put the 2x4 frames together im using a jig so my aluminum frames dont warp when i screen them.