You may not want reptiturf for substrate as it's very annoying to keep clean. If you want cheap, maybe newspaper?

Btw, these tubs are perfect for adult BPs (the 1960 model; the long, flat one at the bottom). It's dimensions are 34 3/4"L x 16 1/2"W x 6"H. Not very tall, but that doesn't matter since they're not arboreal anyway.