An MBA isn't too bad as Master's go, but for god's sake, make sure it's something that is relevant and something you are interested in. I have a similar undergrad, but actually got my Master's in something interesting and good. I think it helped me immensely, and it's nice having a "useful" degree, vs my undergrad. Overall, go for the Master's IMO. If you really want to get on with a major, you are competing with everyone else, regional captains, military drivers, etc, so you want to stand out. Whether it's cost effective, I don't know, but not much is about our profession.