It's interesting that you think you will make more money by getting a masters. My advice is decide what you want to do i.e. what kind of company you want to work for and what kind of stuff you want to do. Then start at the bottom and work learn at every oppurtunity in your choosen field.
Also decide what your motivations are, do you want to play it safe make enough money for a good lifestyle or do you want to take risks and make tons of money, or do you want to enter an academic field because in the real world degrees or masters will only get you so far in the end your motivation and desires will determine where you end up.
By the time I was 21 I had already gained 5 years of real world experience (in more than just work
)
Bear in mind too that it's never too late to try something new, if what you choose isn't working out or you feel stuck or trapped then don't be afraid to take a risk and change the way things are, because you only get one life remember.
Ok enough of the philosophy from me 