career prospects after going to SILS

I'm currently a 20 year-old who just got his bachelor in Japanese (3 years) at university so my level is between N3 and N2. However, I am thinking of going to the School of International Liberal Studies next year. I more or less want to use it so I can better my Japanese skills, to network and hopefully to get recommended by the school to a certain company. The problem is, I saw that this course is 4 FREAKING YEARS which means I would have to spend around 50.000 euros before I can even get a job. While I do have that amount in my bank account it still feels like taking an enormous risk and I don't want to spent 4 more years living off my parents' money. Does anyone have experience with SILS? Are there ways I can do a part-time job (arubaito) inside or outside of the campus? How big is the chance it will help me get a job in japan after graduating? Any help would be welcome. 😔

Actually we 80 percent or more foreigners do some kind of part time job such as work in factory (28 hours per week) or Teachers assistant TA Or resident assistant RA ,so 20 percent or less however get parents support or own gov support,we tell them okanemochi

You have a degree, why are you looking at doing more? If you need some extra strength to things like spoken or written Japanese, do that.