My answer:Why should I do an MBA?
You can use the MBA as a key to open doors.
Building up on that analogy, you first need to know what doors you'd want to open.
There are far too many doors (i.e. career options) to choose from. Walking into an MBA program hoping it'll give you all the answers will only increase the confusion.
Whether you choose the CAT or GMAT, you'd need to be clear about three key parameters:
1. Industry: Do you want to continue working in the technology industry? Or move to Finance, Retail, NGO or some other field?
2. Role: Do you want to transition from a technical role into a managerial role? From being a software developer, do you think you'd do better in a Sales/marketing role?
3. Geography: Do you want to stay back in India or move to another country?
The answers to these (and several others that I haven't listed here) will give you an idea of the 'doors' you should be focusing on. This is when you should ask yourself the same question.
Do you need an MBA?
Scenario 1: If those doors open immediately (without the need for an added qualification), your life becomes simpler. You don't need an MBA.
Scenario 2: If the recruiters in your target industry place a premium on a top MBA degree, that's when you'd know you should go for an MBA.
The rest of the perks - money, lifestyle, growth opportunities - will be a result of your choices.