Um, no.
Me not buying an AP will not cancel out someone else's purchase. That purchase will appear on the distributor's ledger and on Hasbro's.
No. As I explained, the costs of making that other book mean they need to sell significant copies of both to make the same profit. See below.
It is also more profitable to sell two books that sell will 25,000 copies than one book that sells 25,000.
However, if they only release one, they might sell more copies of the first book. D&D has one big audience and not everyone buys every book released every month or other month. One purchase comes at the expense of another. So if you can sell 50,000 copies of two books, that means you might be able to sell 30,000 or even 40,000 copies of one. And that IS more profitable.
Or, and here's the thing, delay the second book by 6 months and have
both sell 30-40,000 copies. This ends up with you having the most money. Oh, and because releases are spaced out, the edition lasts longer and the hobby is more stable. And you avoid edition bloat that causes sales to flag. And you avoid the intimidation factor that costs sales (see later in this post). Spacing out releases is all gravy.
Releasing two competing products *only* works if there's no overlap between the two audiences. Like releasing an action movie and romcom on the same weekend. If D&D had two so incompatible segments of their audience, they've have big problems. (And, arguably, this is what they're doing by releasing the board game and minis along with the RPG products.)
Which one do you think will sell more copies? PotA or a Forgotten Realms campaign setting book?
PotA.
Because no one is going to buy a turd of a Forgotten Realms campaign setting rushed out the door in two months.
PotA is being written by a licenced publisher. Because the D&D team is not large enough to have a book of that size (or the planned two books) ready for March so closely after finishing the DMG and other core books. So why expect them to be able to finish an even larger book that has to be more carefully written and require even more research and feedback?
A FRCS is going to take some time. Talking about it like it's a possibility now is pure fantasy.
Up front the cost is less. That is a fact.
Up front cost only matters to small publishers who have to worry about paying bills while waiting for sales profits to come in. It's not a factor to WotC who has enough disposable capital to order large print runs and let them pay off over time.
And who is to say WotC will make 5 60 pages books? Remember, your argument making too making too many books is bad.
I went with five 64-page books because that's the same content as one 320-page rulebook. 64 x 5 = 320. So releasing five 64-page accessories takes roughly the same amount of work and manpower as writing a single 320-page book. So the production costs for WotC are the same. Which makes comparing the price difference to consumers ($50 vs $125) more dramatic.
Paizo has noted that sales of the first volume in an AP sell best, and later volumes go down in sales. They're doing the same work for less and less money. If they printed APs as a single volume it would have the same production requirements but potentially sell better than the later volumes, leading to higher overall profit.
We should forget that WotC doesn't sell PDFs and they probably sell more physical unites than Paizo. So they print more and that means economy of scale, so cheaper products for customers.
If this was true, wouldn't the D&D books be cheaper than Paizo's books of the same size?
WotC sells far more books for many reasons, not just PDFs. It's audience is just much larger. However, Paizo sells directly. Selling a book from their e-store makes them 3x as much money per copy. And Paizo makes far, far more money per copy from PDFs of adventures and the like, and comparable amounts for PDFs. So they're making money multiple ways that offset the lower sales.
It also means a lot of people won't buy them cause they cost too much. It is just fact. Not everyone can shell out 50$ or save that sum up.
A one-time $50 fee for a 320-page book is far easier to shell out for than $25 for a 64-page book five times. Or even three times.
Yeah, some smaller price point items might be nice. But I'd much rather get more bang for my buck.
Also, that whole intimidating shelve is a argument from forums. It is just as valid as an argument saying that empty shelves will mean games won't buy books cause they feel the edition is not supported. They might be even more numerous than the "intimidated ones".
Do you have any research to back that up?
The intimidation factor of choice has been
well researched for academic papers. People are a tenth as likely to buy when confronted by too many choices.