If you can't afford a rack, a tub with the lid on is the next best alternative to using tanks.
You can pick up a book shelf, nail the shelves close enough together to keep the snakes from pushing the lids up and escaping, add some flexwatt heat tape and ...



It may not be pretty, it may be somewhat of a hassle, but it flat out works, and tubs with lids hold heat and humidity better than most cheap melamine racks.