Plastic tubs online are tough... plastic tubs at Lowes, Walmart, The Container Store, those are quite easy to find. And cheap at $4-13 a piece.

I, too, hate racks but find myself needing to acquire one before long due to space restrictions. Better to go up than out.

RBI is awesome, and I've heard good things about AP and Boaphile, but also check out Herp Enclosures. Those are the lowest prices I've yet seen.