You should be able to get a nice hybrid for well under 500 bucks. Of course you can spend as much as you want to but a bike like this one is perfect for riding around the campus and even on long rides if he chooses. Also remember that it’s probably going to get beat up and rained on etc and bicycle theft is high on college campuses so you probably dont want to spend too much for a bike that is going to be sitting outside unattended. This is a nice bike right here at a good price, and of course you can spend a little more if you want to get one a little nicer.

https://www.montgomerycyclery.com/product/giant-escape-3-306156-1.htm