Target. Most common tub for racks is sterilite 1753,1755. And the 1757 is good for roaches, mealworms. I recently got some of the 1900 models. They are a little less heavy duty. But they are cheaper and in the college section. None have broken except one that I tried to use as a hide inside of a bigger terrarium.
I'm a Big Lots buyer as well haha! I even have the rewards card They usually always have a large variety of all sorts of containers, including the popular gecko sizes.