I don't have the mice, but I can understand that (Who needs easy though? Haha ). I keep my big ASF colonies in 40 gallon breeder tanks, and they seem to thrive. Many times I don't even realize there are babies until I catch them running around.

I'm waiting for those shelves to go on sale again. The regular price is $130 (I'm in Canada), but they go on sale for $99 quite often. Well worth it for being completely adjustable. They can hold several hundred pounds, but still move perfectly with the wheels.