I assume you mean a soft crate? I love elite field soft crates and use them constantly for trials and while I teach. I orginally bough mine from ebay, but now Amazon sells them too. Way cheaper than buying from a petstore. N2N (noz to noz I think?) also makes good sturdy crates that are very popular for dog sports people in this area. I have one but it is heavier than the Elite Field ones I own, harder to set up/down because of the button you have to push, and more expensive.
If you mean a wire crate, Fleet Farm has the cheapest wire crates you can purchase in store and are decent quality. Otherwise i would check amazon and ebay again. I have 2 Midwest crates.