Your from Montana? As others have said, knowing what your gonna tow with will help with that decision. Also knowing if you are camping alone, a couple, a family. Plus in my opinion the Casita and Bigfoot are two totally different trailers! It's like asking to compare a kiddie pool with a olympic size pool. (kinda anyway) Both are camping units with tires
so you can pull them behind your tow vehicle. But each was made to fit into a different camping/rving style, price range, and ease of use. The Casita is perfect for ease of use! The easiest camping unit I have ever owned. But it's basic! The bigfoot was made for cold weather climate and because it's much bigger than a Casita there is more move around room, draw back is it's heavier, wider, etc. If you can/want bigger I totally suggest a bigfoot, if you want small compact then the Casita is the way to go! Let us know more about how you are going to use your trailer so that we may be able to help you find what your looking for.
Too bad you hadn't posted sooner, cause there have been several Casitas for sale
in Montana in the last 6 months. Robin