I think MS would be the most optimum option for anyone’s career track. But as far as the education or the number of degrees are concerned, the more the merrier. I haven’t seen a single person with PhD who does not have a good paying job. You just have to find a balance between your education, personal life and finances. I my case, I wish I would have finished my BS and MS back to back. Although I am saving money since my company pays for about 70% of my education, it is a hassle to manage school, work and personal life. But once you start working, you get a better idea of where you want to see yourself in next 5 years and you can plan accordingly.