Should I keep my school bag simply or go for something more designer?

I liked the simple one and the purple designer one (the second one). But for school, I think, personally, I'd go for the simple one. I wouldn't want to dirty the designer one in school. But for weekends I'd go for the designer one. Or if you want, you should just see which one would look good with your outfits. That's what I do. If it doesn't match my clothes, then I don't use it.