I want to start my own craft business specializing iin military items?

Before you begin, investigate the rights you'll need to create Navy branded gear. I'm fairly certain that like any other brand (Coke, Hershey's, IBM, etc) you'll need to get permission from the Navy in order to legitimately sell branded Navy items. This may be one of the reasons that the Navy items you buy are so expensive. Once you obtain the rights, determine what type of customer you want to sell items to. Do you want to reproduce items similar to those that you bought? If so, you should look for avenues to find customers like you. Once you have the rights and know where to find your customers, seek financing and go from there.