If you're progressing well at the moment, why do an MBA? I realise that it has benefits other than helping your career progress, but none of it is rocket science. I think if you're well on your way to becoming a manager (big step up), you should go for it, get some experience managing, and then evaluate whether you need an MBA to help you progress further or not. I did an MBA because I needed a change in my career, and it helped me do that, but if you're happy with your job and where it's heading, I can't see how an MBA would be a big benefit now.