There is no necessary connection between the student union and the suit. Even if you don't attend the student union, your personal image is still very important. Thought you were a college student. If you like it, and your financial ability can keep up! A better suit is not cheap. A poor quality suit really sucks to wear! There is a saying: you can't succeed, but you have to be slovenly! There is no bad dress, only bad collocation! Pay more attention to the relevant collocation knowledge. With your understanding as a college student, it must be appropriate to fix your image. Can wear their own characteristics and personality!
I haven't attended the student union, so I don't quite understand why I need a suit to attend the student union! Hmm. How interesting