I keep my adult in a 3x2x2ft Vision Enclosure, although it wasn't cheap. Other than going with a glass tank you are going to be looking at spending some money.
Check Kijiji or Craig's List if you are looking for glass. I found a 30gal for $10 (but then you have to buy the mesh lid which will be around $25, and the clips to lock it, another $5-$10).
Don't let anyone, ever, make you feel like you don't deserve what you want. - Heath Ledger
Always check craigslist! Especially if your driving to a different location for something, i never found anything appealing in my area but craigslisted where i was going for holidays and got 2 vision v332 with the extra 15$ vent for 85(both of them) this is how hoarding starts i think. And is the $1 a gallon nationwide?