The Lowes by me sells PVC board starting out at $16.98 for a 3/4 x 5 x 8. I am unsure if they will cut it for you, however I know they will cut lumber so I don't see why not. The first two-three cuts are free and then 75 cents after that. I have drawn up plans to build a snake rack from two sheets and the whole thing from 10 CB-70 tubs, pvc board, to the Spyder Robotics Herpstat 1 will cost me $330. (The tubs and herstat alone is $230 of it.)
Just curious, while I was looking on YouTube for rack ideas I have seen people sandwich the flex watt in between the foil tape. (Layer of foil tape on the shelf, flexwatt, layer of foil tape covering the flex watt completely) Would this be the way to go? The foil tape can withstand temps up to 250 degrees and the PVC board if flame retardant. Maybe someone can point out how this wouldn't work, I know YouTube is not the best place for rock solid information.