I was wondering if you possibly have a picture of your cage handy? I'd really like to see what that looks like.I paid 32$ for my piece of coroplast, 48in by 96in. It was a little outrageous.
However, double check your home depot. Ask for plexiglass instead of coroplast. They should take you to an area that has both. Most people at home depot, I've discovered, do not know what coroplast is. You might have to buy more than one sheet depending on your project.
As an alternative I used vinyl (laminate) flooring for Penny's cage. I now use plastic cube sides that I found at dollar general. You might be able to find them.
I'm absolutely in love with your cages! I love the pink squares! Just one question, is the "plexiglass" actually plaskolite? This stuff? http://m.homedepot.com/p/Plaskolite-8-in-x-10-in-Polystyrene-Sheet-1S08104A/202043333/http://www.hedgehogcentral.com/foru.../1611-cage-setup-examples-102.html#post496650
This is the cage I use now. The bottom left cage is Winter's. I am still using coroplast for him. This was a huge project for me. If you have any questions please ask.