Under no circumstances do an MBA with less than two years of work experience. You won't get into a top ranked programme and if your programme isn't top ranked you'd be better off doing it by distance education while working. If you were going to do a second entry degree a J.D. would be a much better idea.
An M.Sc. in CS probably has a better ROI than most MBA programmes, and it'd let you compete for jobs that wouldn't be available to you fresh out of a Bachelors. The thing is you might be able to get enough real world experience in the time that you'd be doing a Masters that you'd be at the same level in the same time, but you'd have been earning and making contacts in that time.
If you love what you're doing keep doing it until it palls.
Don't pay to do an M.S. get in as a Ph.D. and bail once you've got what you want. Alternatively come to Europe where education is dead cheap. Karlsruhe in Germany has a fantastic CS programme, and it's a beautiful, beautiful city.
For an MBA, consider INSEAD. It's highly ranked and it only takes one year.