Let me explain the situation more fully.
We’re a small publishing firm (since 1982) and for a new nonfiction book we usually bid out a run of 1,500-2,500 copies (or what our niche pretest suggests would be a reasonable buy rate, minus about 30%; if it says 5,000 would might buy the book from direct mail, we will print about 3,500 copies.)
Conversely, once printed, our books will eventually fall into one of three categories. living, dying, or dead.
Call quickly, our dead books are going at a huge discount, in lots of 100 please! I’m joking, but we try to keep all of our books available in modest quantities, unless we update them, in which case the earlier edition dies and is replaced by the update. We get the small reserve by ordering in batches of about 25 copies, POD, usually from Lightning Source, which delivers them at our door in just a few days. (We don’t order individual ink-on-paper paperback books POD.) That takes care of the dead books, which means the demand is so low we sell our reserve stock down to 2-3, stop listing the book, and put a RIP sign in front of the bin.
The living books I mentioned above. They are the first-print version, and if there is robust life in the sales, we might return five or ten times for full press runs.
The issue is usually the dying (or not-so-living) books, where we need to occasionally stock 50-100 or so more books. Those we buy from a short-run digital press (often just a different branch of the full press) in what we guess to be about six-month quantities. We keep doing that until it’s obvious that the book really is dying, when the POD printing kicks in.
The smaller the run, the more it costs per book—and we rarely increase the cost to the buyer once the book has been around for a year or so. That’s why you might get a solid first run, a lesser short-run digital quantity, and you keep the PODs to a number you think you can sell (but no more).
Looking at various bids, I’d guess the books from the full press first run of 2,500 cost just under $1 each, shrinkwrapped, plus shipping (about 25 cents each).
The short-run digital cost for 250 books, shrinkwrapped, was $3.55, plus shipping (about 35 cents each).
And the POD order, for 25, not shrinkwrapped, with the original fees included, was about $4 each. The shipping was high: about 65 cents each.
That’s it. Our printing process designed to produce the same book (same cover and contents) to sell at various stages of the book’s inevitable demise, while keeping our warehouse totals as low as practical.
I hope that helps those of you who asked. And the rest too, particularly if you’re new to this.