Companies pay what the market will support. If your son (or anyone else) will work for that amount…that is the market.
Why would a company pay more than the market price?
For a lot of people, $25 an hour is a lot, but, of course, at his old job, he made much more than that. When his school’s owners decided to close the school, he just wanted some part time work without the Chicago drive time, and this present job is 15 minutes away. They’re writing a grant for him to be associate director, and he’ll get a big raise, but my point was that many people who work in college or university jobs, even in big cities, make a relatively low wage.