The story did suggest that some books were cheaper at the coop, and that he would buy those. Otherwise, why go at all... get 'em all online.
I'm not opposed to shopping for the lowest price, and buying from that source. If the bookstore had its prices online, it would be the same as shopping between Amazon and Barnes and Noble online, and buying from the cheapest.
I have more of an issue with shopping at a store that allows you to see, try, and compare a product, taking advantage of salespeople to help you... and then buying online. There's rarely a need for that kind of shopping with books.
Whether they like it or not, even Harvard has to compete with the marketplace, and that includes online sources. If they deal with that by throwing out people who are aware of other places to buy their books, how long do you think they'll stay in business? How long would you want them to stay in business?