Red Flags for DMs?

[icefractal]

The Mercane are a canon version of that. They don't have a magical Walmart, but they have vaults of magic items on the Astral plane, and they can trade with each-other very quickly. Get in contact with a Mercane, show you have the payment required, and they should be able to acquire nearly anything in a day or two.

Even at lower levels, I think the "magic item fixer" (in the Shadowrun sense) model makes more sense than magic shops with items just sitting around. You don't go buy that Carpet of Flying off a shelf, you talk to someone who knows who's interested in selling and what. If they can track it down, they'll arrange the sale and act as a trusted third party. They might also sometimes buy items themselves for later sale, but those would be stored in basements or unmarked warehouses, not such an easy target for thieves. How do they get paid? The mark-up between selling price and buying price.

Which also implies that if you're willing and able to do your own legwork, and figure out who's trustyworthy (and convince them the same about you) yourself, then you can get magic items for less, potentially as low as the selling price. In a way, crafting that's open to non-casters.