@AaronLoeb
How to put it?
RPGs are a relatively small market, D&D and D20 constitute a large portion of that market, with the D&D share being far larger than the D20 share although D20 has far more products to go around. Forgotten Realms is a brand name that has a big following, both within the RPG business as outside it (novels), and thus any book that's produced for it will have as a result a far larger following. Also FR is the 'core' setting for D&D (although officially it's supposed to be Greyhawk), this all makes FR products appeal to a far larger audience, you might want to say FR has a large core group. The same goes for Slaine and Judge Dread, brand names that have a large appeal outside the D20 branch, and thus have a large audience/core group. Products that use brand names have already something that 'normal' products lack, fame/infamy, thus not really comparable to products that do not have something like that. Kalamar also has a 'plus' because it carries the D&D brand name and thus also has an 'unfair' headstart because of it (i think it still has a far smaller audience/core group than for example FR). Scarred Lands is on the other hand a 'new' settings that had to gain a following, it did that through products that had a primarily other function (Creature Collection 1 & 2, Relics and Rituals, location books). I'm pretty sure that The Divine and the Defeated did worse than CC1&2 or R&R1&2, The Scarred Lands Campaign Setting even worse (if someone has the facts to the contrary, please do tell). Through 'cheap' 'crunch' books SSS got the ear of a far larger audience and as a result got trough to a lot more people with their SLCS than if they had not 'softened' up their audience.
TBotR on the other hand neither has a brand name nor a following, it has to sell on it's own merrits, but it also has a far smaller audience/core group because it doesn't have a brand name or a following. It already has a pretty small audience/core group, thus not that many people who'll buy it and because of a comparitively high price it will probably land in less people's hands than if it was priced more competitively.
Let me paint you another picture, the laptop market. I bought a laptop at $2500, a perfect machine very great value (compared to other brands it has way more bang for the buck, so to speak), but it certainly isn't a cheap laptop. Most consumers wouldn't consider buying one at that price, simply because they find the price to high, even though it's a magnificent machine compared to cheaper solutions. Cheaper solutions still sell, either because they are cheap or because they have brand names (such as dell, compaq, ibm, sony, etc.)
I still have only browsed through TBotR, but from what i see it's high quality (i intend to read it from cover to cover, but am still catching up on my Battletech novel reading), but does that really matter? Would you buy the same book at $100, i wouldn't, maybe some would. The point is that although you might increase the price of a product less people are going to buy it. I'm not saying that i know the formula of how price (and hundreds of other factors) compare to how much units are sold, i also do not think that anyone else knows on these forums (although some seem to suggest they know). All i know is that higher price than the markt leader will result in less people buying than when the price was equal to that of the market leader and more people will buy it if the product is priced below that of the market leader. I also know the higher the price, the higher the profit margin per book. The gamble is how do you balance that? GR chooses for a higher price compared to NG, as a result NG will have a deeper market penetration then GR (NG also has the added benefit that it uses WW channels for sales). I don't know which way is better, but what i do know is that the chances of a retailer selling 3 NG products is higher than selling 3 GR products. I'm not saying that's the most important thing in the world for me, but it is for a lot of other retailers...
I know exactly what niche TBotR fills, exactly what you described, a setting book that's hot plugable into any campaign setting that not already has it's own pantheon of gods (mostly homebrew settings). That's exactly what i realized in the piece you quoted me on, i realized that TBotR might not have been the most perfect example here. But that doesn't mean it's any less valid, there are other niches out there that are not filled by dozens of products, but that isn't the all clear sign to make such products more expensive than the 'norm'.
I certainly won't force feed my customers products. Knowing what a customer wants is a complicated process, very few come forward with "I want a God book that's goes very deep into it's individual gods and churches, customs, etc. It also needs to be BIG, is not for an established campaign setting, don't care wheter it's pretty, and don't care about the price.", these things have to be pulled from the customer. Generally i give my honest opnion and how said product would fit into their 'search parameters', it's cons and pros, etc. In the case of TBotR it's con is it's price, and depending on the people i talk to that's either important or it's not. Let me press this again, TBotR is NOT the same as Deities and Demigods, Faiths and Pantheons, or The Divine and the Defeated, maybe comparable to Gods (AEG), but i don't know for sure. This was pretty clear the first time i browsed through the book. The problem is that there are just less people looking for TBotR than for something like Deities and Demigods or Faiths and Pantheons. Also, the $40 line seems somehow magical, not many people are willing to touch it, it already was a problem with WotC books such as FRCS, WoT, and CoC, and these products where in full color. The problem i see is not that you don't have a good product (from what i see it's an excellent one), but that you have an 'expensive' product that only appealys to a rather small audience/core group.
Btw, i still have two TBotR in 'stock' so, them not seeing it is highly unlickely!
Now, please tell me if i'm wrong or that you have another opinion on the matter, but this is how i currently perceive things. This is not fact just an observation. And i think this discussion is highly enlightening ;-)
For i forget, i think that sales are extremely local, some locations on this planet sell high volumes of a certain product for reason X, but another location sells not a thing for a whole battery of other reasons.
Also, predicting the RPG market and in particular the D20 market is like trying to look through a huricane. One moment it apears the storm is over,only you realize your in the eye of the storm instead of outside it. To many factors influence the market at the moment (economy, war, computer progress, many publishers, etc.).
In fact, all evidence is to the contrary, with it selling better than projected.
I'm the cumpulsive curious type. How many sales where projected, and how many where actually sold? Is there a second printing comming?