I went back home empty-handed and re-checked the website. Sure enough, no mention that the store would be closed for almost two weeks. A page on textbook buybacks even mentioned that they would be taking place from January 2nd to January 4th, in the bookstore... despite its being closed?
Granted, this is my first year at university, so maybe there's a logic here that I'm not seeing, or maybe I just don't know yet that this is how things are done. But I think that (1) not announcing anywhere except the front door that the store will be closed (2) not reopening until the first day of term (3) advertising in-store book buybacks taking place during this closed period... is pretty lame service.