I am seeing prices of $280 for .5 thick 48 x 48 inches of Plexiglass.

Gaskets are not a problem... McMaster-Carr carries lots of materials.

Just saw this in their catalog...

Impact-Resistant Polycarbonate Sheet, 1/2" Thick, 24" x 48", Clear $178

Bet that's "the stuff."

Overall, the idea seems like a good one to me... I'm just wondering what the down sides are...