Right now, there’s a goldpiece gap in D&D.
I’ve been extracting the money with large projects: trans-oceanic voyages, picking up a ship, maybe maneuvering large numbers of cattle around. You never know.
Okay, so we can talk about lands and people — I wrote a few articles on that before. But what about the wonders of the elves and dwarves, wrought in skill before the Daughters of Eve reached their shores? By the books, if it’s armor, you can spend money to improve your capacities; if it’s anything else, you can’t. But that’s silly, because I really want there to be elven rangers combing the woods with their cloaks and boots, and who doesn’t know the axes and armors of the dwarves?
Of course, one could go too far; flaming swords and staves of the archmagi probably shouldn’t be on sale in the market square. But mithril coats and adamantine daggers? Those are just metals; if you can mine it and smith it, you’d better damn be able to sell it to a cash-flush adventurer or noble.
Platemail is kind of just chainmail +2. Oh, there are some differences — 20lbs of weight, a higher strength requirement, an immunity to the tender caress of a rust monster, a tendency to glow around wands of detect magic, but we are folk of the world, gentle reader, and will not quibble over trivialities.
Platemail is 1500gp and chainmail is 75gp, negligible; +2 Armor is a Very Rare magical item by the book. It’s also literally just +2 to a d20 roll (actually not even, but you know what I mean). At the outer edges (from 18 to 20, for instance) that’s a scary number, but at the inner edges (16 to 18) that’s not so bad.
I’m going to cheat. Yes, technically Platemail is Chainmail +2, and +2 is Very Rare. But if we consider it (merely) rare, things get a LOT easier for us.
For one thing, per the DMG pg 130, when selling magic items, the “rare” base price is 5000gp, within a forgivable distance of 1500gp. But if we were to leave it as a Very Rare item and try to pull other Very Rare items into standard distribution, they’d be extremely cheap.
I’m actually going to cheat twice: when a monster can “only be hit by magical weapons”, weapons +X don’t count. It has to have a property or be silvered for real (or whatever). The spell magic weapon still counts as, uh, magic though.
We’ll skip over consumables for now. I’ll write about them later. Potions and scrolls and spellbooks are, in fact, potions and scrolls and spellbooks. Tadaa.
So, from that point of view, sticking to the more mundane-ish items:
Rare (5000gp, down to 3000gp when buying from the right kind of settlement; half cost if it is a simple weapon or a “low tier” armor):
Ammunition +3 (10 pieces)
Armor of Resistance (this is basically a poor man’s dragon scale already…)
Cloak of Displacement
Wand of the War Mage +2
Gem of Seeing
Portable Hole (Wile-E-Coyote could buy ’em, so can you)
Uncommon (500gp, down to 300gp when buying from the right kind of settlement; half cost if it is a simple weapon or a “low tier” armor):
Ammunition +2 (10 pieces)
Wand of the War Mage +1
Boots of Elvenkind
Cloak of Elvenkind
Cloak of Protection
Gem of Brightness
Bag of Holding
Cap of Waterbreathing
Decanter of Endless Water
Goggles of Night
Javelin of Lightning
Lantern of Revealing
Common (100gp, pretty much as a floor.):
Ammunition +1 (10 ammo)
Silvered weapon (10 ammo)
So: that’s a little interesting.