The best price is Petco during their dollar per gallon sale for a 40g breeder tank. They are pretty small though, in my opinion. It's better to build a larger one on your own or have one built for you by a shop like K&M Dragons. It's also much easier to have front opening doors rather than having to reach in from the top constantly. I keep a 40g breeder tank on hand for a rescue situation but I consider it a temporary emergency tank rather than a full time enclosure for an adult.