I can just reiterate what has been said before really
1. PhDs are only really required if you want to work in high level research or lecture – most game jobs don’t require them and in fact since PhDs usually involve a lot of solitary work they may think you are not suited to team work because of it..
2. There is a lot of valuable experience here on these forums and people who have experience working in game companies and trying to set them up. We don’t want to put you off but set realistic goals for yourself and talk to those who have tried it already. Could save you a lot of time and expense..