The danger of going for PhD is that after 5 years or more of studying, with all the time investment and academic achievement, you no longer have as much desire or motivation as initially. I think this partly explains many legendary founders started their start-ups very early: Bill Gates, Steve Jobs, Mark Zuckerberg (not considered legendary yet but on his way), etc. The more you how hard it is to start a business, the less time you have left, the more unlikely you actually start one. If you think you will start a business someday, why wait any longer, start one now. Good luck!