What's the advantage of having a Master's degree?

Your question answered with questions:
- is a masters degree required to be competitive in your preferred field?
- which type of degree?
- what is your motivation for pursuing the masters? Personal or,professional?
- are your earnings (professional reasons) going to make the degree worthwhile? What is your simple pay back?

The answers to those tells you whether or not it's an advantage

job opportunities, pay

At one time, a master's degree was better suited for professionals that had been in the industry for a while. Students would learn as much from the other people in the class as they did from the class itself. Like others here have said, though, it depends on what you do with it.