You're talking about a Masters, though. What do you want to get your Masters in? Japanese? If so, why not major in Japanese in the first place? A close friend of mine who is fluent got his Masters in Japanese from the University of Massachusetts but he had majored in it and studied his rear end off during his undergraduate experience.
And nothing, absolutely nothing, can replace actually being in Japan and being surrounded by the language. Learning a language is a lot like learning to play an instrument--practice makes perfect. Same goes for reading the language--just like reading music and being able to play what you read.
Money is a concern for just about everyone trying to learn a new language. You've got to weigh potential cost with potential benefit. If you study Japanese in college, you can gradually achieve fluency but it won't be as fast or effective as being in Japan. The thing is, if you go to Japan to study, you can't just be there for one semester or so--it will take at least three months before you speak "survival Japanese" and a year of being in-country to get used to basic Japanese and have the ability to discuss a variety of conversational topics. I spent THREE YEARS in South Korea learning Korean and I still couldn't have complex conversations about abstract topics like politics, history, art, or literature but I could make small-talk about the local baseball team like a champ.