if you want to further enhance your skills and knowledge then I advise you to go to college. Here in our country we have vocational courses which is way cheaper and could take only a short period of time, about 2 years.
But most of the companies here prefer 4 year courses.

College is advance ladder of educational system that would prepare you to you future chosen career. I suggest that you go for it, not all have that privilege to go to college.