When I was visiting family a couple of weeks ago, I had a chance to go to Grand Rapids and shop a bit at the Baker Book House bookstore. It is basically like any other Christian bookstore, but then you go to the back and there is this massive library of used books for sale, Baker books and all other publishers. I did not find much there of interest to me and found most used books overpriced (compared to Amazon marketplace). There is another section with discounted Baker books that are new and recent. I definitely picked up a few items there, most of them 60% off. I was hoping to meet some Baker Academic folk, but the actual publishing office is not at the same site. Oh well, maybe next time.
If you are ever in GR, this bookstore is well worth the visit. Save up first.