OKay I will give you a couple good sites to read, but a quick run down. I have none available till spring, but there are some in the classifieds.
Depending on what you want as far as color, The yellowheads ones run about 50.00 each The aquaflames, you can pick up for 20 - 40 a piece.
The desert collareds/ C. bicinctores about 20.00
The most expensive species are the Baja collared/ C. vestigium around 300.00 (pricey not many people have them)
and the Dickersonae, I did not have any of them on my site, they run in the 400.00 range 
So most stick with just C. collaris in that group is the yellowheads and aquaflames, and many different colored ones. and more affordable.
Lighting, Basking 100 - 105 / 110 acceptable rest of tank high 80's to 90 and need uvb lighting also, or natural sun light.
Home depot washed play sand for substrate. And yes they are bug eaters.
Crickets are thier main diet, with superwoms, moths if you can catch them, they love them, grasshoppers, they like waxworms, spiders.
Here are a couple good sites to read, one is a forum buddies Will Wells, info and many pics ! And the other is a friend, also, good info.
Give them a looksie, and if your still interested, and have questions just come back to the collared forum, we will be glad to answer all your questions, 
http://www.mountainboomer.com/crotaphytus/
http://www.collaredlizard.com/articles.htm
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Eve / PHEve