KM.. see post #47... right under yours..
For reference:
One of the favorite places in my main D&D campaign world is a 'magic shop' run my an Elven adventurer now long since retired. A former PC, like many NPCs of note in this particular milieu, the proprietor is constantly testing and experimenting with various magical potions and spells, making entry into the store an adventure in itself. Players have opened the door to the entire place being coated in shades of orange, the shopkeeper unable to deactivate a self-inflicted polymorph and the "stock boy" (a 9 ft. troll) being lost amid the shelves for hours on end.
The shop carries, buys, sells and trades everything from magic items to spell components and is willing to identify and/or translate items and ancient texts to the best of the owner's ability. His colorful antics, foppish clothing and slightly effeminate English accent are all a carefully constructed facade to hide his vast wealth of arcane knowledge and phenomenal spellcasting ability. Make not mistake, he players the clown but is a deadly combatant. And of course, the stock boy is a troll.
For regulars and favorite customers it is not unusual for the shopkeep to preform identifications free of charge, order special, hard-to-get items and even teach a few unique spells of his own creation.
This to me is far from a Magic Walmart and I can safely say my campaign would not be the same without it.
Specifically, the poster notes that this is "far from a Magic Walmart." Rather, it's an eccentric shop run by an eccentric one-time adventurer and current spellcaster. As an expert in magic items who exists in the setting, it makes sense for this NPC to set up shop. In the "default D&D" assumptions, other adventurers exist, so this would fit right in in Eberron or FR or most homebrews who use that default D&D assumption.
So I can't see how calling it a "MagicMart" is anything other than trying to reduce his flavorful, time-built campaign element into some harmful problem waiting to happen when for him, and his group, it quite obviously isn't.
I have seen 'Walmart' approaches to buying magic items, and invariably the results were not good. Perhaps its only my group that constantly has a Thief who sees a 'WalMart' as an opportunity. DM-NPC's and dues ex machina have been the only means to protect such a gathering of magical artifacts.
Again, you call his adventurer-run shop a "Walmart" approach, which he specifically denies (and which, honestly, I don't see). You falsely assume there's only two ways (two negative ways, at that) to stop some potential "thief" from robbing the place.
For me, if a GM has a shop, such as the one in post #47... I am positive the game will end poorly when the Thief uncloaks the inevitable loophole in the shops protection scheme and gets unceremoniously killed just prior to cleaning the place out.
...and yes, I am speaking from experience.
And then you go on to claim that your experience is one that is universal? That all GM's with even flavorful, historic places where magic items and magic supplies can be bought and sold will have a problem because someone will eventually steal the items?
There's a million and one ways to protect a location in D&D without the abuse of DM power or the strangling of verisimilitude. There's even more ways than that to "handle" a thief who *does* rob a place like that that the world already has in place.
First thing I would think of is "You are meddling in the affairs of wizards. You'll be lucky if being unceremoniously killed is the only thing they have planned for you." Second thing I would think of is "Troll stock boy."
So, your complaints with even a sensible magic shop fall very flat, and, indeed, sound more like you condemning the concept without an understanding of the concept, in other words, showing how a campaign without magic shops (like yours, presumably) is better than any possible campaign with magic shops (like The Green Adam's).
Your experience sounds rather poorly handled to my ears. Don't assume that privately owned stashes of magic items are always so easily accessed or obsessed over.