I agree with Zina on this one...It'll be cheaper in the long run to go with a pvc cage that is built to hold humidity and heat. The larger exo terras can easily range $300 or more and you will need to insulate the sides, buy glass inserts for the top, do heat tape on one bottom side, and use a CHE or RHP for heating ambient temps...Which can be hard to do, as you don't want the CHE sitting on glass (it will crack) but you also need to keep humidity up.
If you go with a T8 from AP and have heat tape put on one end, you'll basically be paying what you would just for the Exo itself. You will need a good t-stat with either setup.
I own an exo terra x-large x-tall (3x3x18") and it is crazy heavy and has been hard to deal with...and I'm keeping tree frogs in mine.