MBA with a BS in Comp Sci, pros and cons?
When you say you are interested in business, do you mean you want to be a manager? Or in finance? Or are you "academically" interested and you simply want to learn about things like OB, finance, accounting or Ops?

If the latter, then I suggest online personal enrichment programs (like coursera, etc.).

If the former, then an MBA may be worth the time and money; many companies want people with an MBA for certain positions (this is especially true of consultancies). Other companies view MBAs as a cliched, cookie-cutter education and avoid them.

You need to figure out what kind of career path you want and do some research regarding the benefits of having an MBA for that path.

As a datapoint: I am a programmer with an MBA (from a top 40 US university). It was not worth it.