Don't forget the state & local lisences needed as well. Insurance and all that hppy stuff is a neccessity too. As I've seen other's looking at that same route thought I offer this so as you don't get dissappointed as they did. 1st -Don't expect to get rich, it's not a big dollar busness in most cases. 2nd - having a FFL doesn't equate to being a firearms expert. I've seen many get this one wrong.
Best of luck with it!