I personally work at a Petsmart and unfortunately when i'm not working, my co-workers do what you just did. Well they only recommend a 20 gallon (which is still too big), but some people do just come in and buy a 40 gallon and spend $450 on the setup. I personally tell people to get a sterilite 12 qt storage container, but some of them just want to buy something at the petstore, so they waste their money on the $40 5 gallon critter cage. Unfortunately most people find bp.net AFTER the fact and thats the issue!