I'd say get a leo, a fat tail or a ball. Cresties run the range from 40$ to 160$ (that I've seen at shows..we won't mention the green flame at a price of 1500$) That includes subadults. But if you don't have the caging ready to go, the cost in plants, water dish, baby food, CGD, and vitamins and calcium dust (if you dont' have vit and calc dust already) is going to cost you some more money overall (which you may not have factored into your costs). Cresties also need more vertical space, so keep that in mind

However, if you think you can get all that stuff and it's not a problem, it's all up to you I really don't know anything about fat tails, other than what they look like, generally easy to care for, and they're ground dwellers.

I would also suggest you buy from a good breeder (keep captive bred in mind!). Not to knock the small hobbyists out there, but there are a few out there that are just out to make a buck, or don't keep as good care of the animals as they should...

Anyway, I hope you find something you really want that you can afford at the show