Can I buy dog crates there?

Absolutely

Yes it's very common for them to have dog crates there usually more than one in the prices are great. I was there today and they had two or three they were in great shape and one of them was huge is more like a kennel and looks almost like new. I think it went for 25 bucks

You will need to visit the store as every day their is something new which people do donate to this store which does help the Arizona Humane society.