Hi James, welcome and thanks for joining, it can be an expensive hobby but at times some of the vendors listed have sales, also you might try reaching out to your local garrison that can be found in the where to start section as they may have members that want to sell kits so they can get another type. In any case look up the build threads here on the forums and see how they are built. This may aid in your decision to build or have it built for you. There’s lots we can say but the best place to start is here and attend local comic festivals where the 501st are attending and talk to the guys there, we are all willing to talk and help if we can. Best of luck.
Wormy