To John Q. Pesant who has never been 10 miles from where he is born the ability to conjure creature from thin air is terrifying.
Aye, perhaps true in Lovecraftian style of magic. But keep in mind that isn't normal by the book. John Q. Peasant, in a normal D&D world, has certainly seen creatures conjured from the air, melodies strummed from nowhere, seen wounds knit at the behest of the deities, and maybe had his daughter hit on by a bard using charm person. Magic isn't rare, in a default world, and I don't know that there's a problem with that, aside from personal preferences.
Humans had some sort of market economy for most of recorded history, however. I mean, that's why coins were minted, right? So it shouldn't be so surprising if someone tries to make a buck from magic items...
Before the gold standard there was the goat standard.
I think that the idea that a fantasy culture's mindset (D&D or otherwise) should mirror 21st century Earth (or even 13th century western Europe) to be somewhat silly. If we insist on looking at Earth culture, though, then look at 21st century Japanese culture, for example, and compare how different it is to other societies... The suggestion that one should "expect" something in a fantasy culture is dubious, at best. Rationality is not a prerequisite for a society.
You'd be surprised, perhaps, at how many detailed and highly academic wars are faught over what constitutes a culture and how different it all really is.
But aside from the fact that no one can ever know any culture in a true sense, the fact that most of the players of D&D are from 21st century Earth pretty much mandates that a lot of the game's characters will share very similar aspects to that mindset, because as in-character as some players can get, they ain't professional actors, and it's impossible to use the method to convincingly play a fantasy creature. It is reasonable to expect something from a fantasy culture in the game as presented in the rules, and it should be reasonable to expect anything in any homebrew, too...that's kind of the essence of verisimilitude, the fact that even though there are dragons and fireballs, things work in a somewhat predictable fashion, even if it's not the same as they work here. Of course the fantasy culture's mindset is going to mirror a 21st century Western mindset for the most part -- the fantasy culture is being created by those with that mindset. And even when it tries for something else (like 13th Century Western Europe), it's not legitimate, it's not accurate, it's just a 21st century take on some other culture. Part of the strength of the new edition, I believe, is to embrace that rather than dismiss it. They make things work on their own terms rather than trying to interpret someone else's terms, and invariably get them wrong. Like a "translation" of the Qur'an, the moment you try to understand someone else's culture, you're missing an essential nature of that culture. So D&D just makes it's own, and makes no apologies for it, and says you can change it and tweak it all you like.
If your game includes PC spellcasters, then you don't have a strong Howard/Lovecraft feel. You have an arbitrary feel.
So, what, every time a CoC gamemaster allows a PC to learn from a tome of lore, their feel is all of a sudden arbitrary? And what's so bad about an arbitrary feel, as long as it's fun and there's enough verisimilitude not to ruin that fun?
the last PC spell caster was a Priestess of Set. Once after defeating a group of dwarves she sacrificed them all to summon a powerful Daemon. Since then she's taken to sacrificing the occasional slave/villiager to her Dark Master.
Sounds pretty typical Evil PC Spellcaster behavior, really. And a lot of fun to boot.
Well, I also would say the artifacts are NOT normal items. They often are intelligent, or sentient sometimes in ways ordinary people don't understand. The very nature of an artifact makes it difficult if not damn well impossible to sell. And naturally the artifacts that possess users aren't going to allow themselves to be sold either.
This, I think, is where the break occurs. Potions are like expensive neccessities. Magic weapons and armors are perhaps more like expensive appliances. When you get to the +5 level, you're talking jet planes and works of art. Artifacts are another beast entirely. To a certain extent, intelligent magic items are similarly that higher level of magic item. Artifacts don't even include a market price -- the message is that PC's shouldn't be the ones creating them. Unique convergences of deities and epic-level spellcasters do (which is why epic-level stuff includes such epic item creation). They're not "just another piece of magical equipment."
A magic sword, in default D&D, isn't some great and wonderous power from beyond mortal ken. The Book of Vile Darkness is some great and wonderous power from beyond mortal ken. A +2 sword is just a really nice blade. Still out of the realm of most peasants and commoners, but definately not out of the realm of, say, the captain of the city guard.