If you want an "escape proof" plastic tub without having to use binder clips and such, and don't mind paying the extra $ for it, check out the Really Useful Box at Staples/Office Depot.

You can use the 4L or 9L for a hatchling (they have the same floor space, the 9L is just taller) and the 33L or 50L for an adult (also same floor space one is just taller). The 4L is $7.99, the 33L is $18.99.

These boxes come with an escape-proof lid and the bottom is raised up a bit which is perfect for the UTH. It is very durable.

Also, when I was in the Daytona Reptile Show there was a booth that sold plastic hides and water bowls of every size for very cheap. We got hides and waterbowls for hatchlings for 99cents each.

Just my suggestions.