plexi glass can be cracked, which is why i am switching to lexan, costs more but it wont crack, you can bend it in half and it wont crack like plexi. the only reason it costs 250 is that everything from home depot and lowes is so expensive for the plexiglass and aluminun. If I did ten cases and bought from plastic and metal suppliers it would only cost about 100 a case for each one but most suppliers have minimum orders in which you would need to buy enough material to do a few cases. sheet metal could probably work also if thats the look you wann go for, and yes they are heavy, about 40 lbs. heres a breakdown of the $250 for skibum:
9/32" plexiglass, $25 per sheet, 3 sheets needed comes in 2'x4'
1/4" mdf, $5 per sheet, 3 sheets needed, 2'x4'
1" aluminum angles, .050" thickness, about $8 for an 8' length, about 9-10 needed
about 300 rivets, $12
1/2" aluminum angle $5 per 8' length, about 3 needed
i get the corners and hardware from stew mac
the inside is a polyethylene foam i get from a fabric store, about $30
sad thing is from a plastic supplier i can get a 4x8 sheet of lexan for less than the price of three 2x4 sheets of plexiglass from home depot.
hoped that helped