Tenant Storage in Basement - how to contruct the storage units

[Eric Hathway]

I want to have storage units built in the basement of one of my buildings to generate extra income. My handyman said he could make them out of plywood and studs. I saw some wire cage structures, but they are much more expensive ($400 each for a 4'w x 5'd x 7.5'h), I had a fence company to quote me $2000 for four units of the same dimensions listed above. Does anyone have any opinions/comments/pictures/recommendations of what they use? What size would you make?