I’m a senior at Cal State Fullerton (and a mom of 3 one of which starts college in the fall)…
As a history major, I have an absolute TON of books. I buy most of my books online a places like half.com (which is part of ebay), Amazon.com, and other textbook places. All you have to do is google “cheap textbooks” and tons of sites will pop up.
DRAIN THE SWAMP, #MAGA VOTE TRUMP 2020!
It takes some effort to shop around on them, and you have to figure in shipping time and costs. Sometimes it takes up to 2 weeks to get the books, plus shipping (these suckers ain’t lightweight). But you can find really good deals.
If his classes or bookstore will give him the ISBN numbers, you can start shopping right away. However, they usually don’t put that stuff out until near the end of summer. Also, some campus bookstores will do price matching if it’ not off a site like half.com. So shop around and have fun.