I was having a hard time finding shelving and display units for our shows... everything was either enclosed, too expensive, or weighted more than a Buick... So I built my own. You can see then in the picture. They are modeled to work with 4' tables... in this case I had 8' of booth so I used two of them. They are covered with stuff, but you can sort of make them out.
Stats:
Poplar with wood stain,
4' long, 9.25" deep, 18" tall (Each)
3 LED lights in the underside of each shelf.
Back brace is a regular bookshelf brace, front braces are ornamental braces.
So light a child cold easily carry one.
Overall cost about $150 for both plus an afternoon in the back yard cutting and sanding.