Nice timing, Adam and I were just talking about treasure, equipment, and all that.
First of all, there are some obvious useful items we haven't included yet, scroll being an obvious one. Those will get added, which will give some higher cost options for all that gold.
Your conversion from original D&D modules sounds about right, and we'll eventually put together some guidelines. We don't want to be too prescriptive, but I also have the same problem - with this made up currency, is 100 gold really a good reward? We'll probably structure this like the Barter charts, "1 Gold is the going rate for..."
I'd suggest dangling one or two magic items per adventure as rewards, and then adding others as you see fit. If you're designing a dungeon, add an item or two that they may not get to, or have to do extra work for ("offer an opportunity, with cost"). Whenever possible, make magic items interesting - there are already a few examples, but we're working on better ones. A magic item should almost always have a move associated with it, flat bonuses are a little boring.
It's important to note that magic items aren't explicitly needed, like in some editions of D&D, but they are fun. Give them strange esoteric moves, give them sentience, just don't give them away because you feel you have to.
Might as well also offer a preview of what we're thinking for "encumbrance." (Quotes because saying that word brings to mind horrible charts and bad rules, but we want to make it awesome.)
There should be some suggestion of how much the players can carry, in particular since that plays into carrying ammo for the purposes of moves that may deplete it. We could just say "whatever makes sense," but I honestly have no idea what makes sense for a fantasy warrior to be able to carry while fighting.
So we're thinking each class will have Slots (bad name, I know, we'll come up with a better one) and items will have Weight. Weight defaults to 1, so if an item doesn't specify a Weight it's 1. Light things are 0, heavy things are 2, unwieldy things are 3, and so on. A dagger or wand is Weight 0, a short sword is Weight 1, long sword or axe is two, some huge hammer is 3.
A character can carry total weight up to their Slots (+Str?) no problem.
When you make a move with too much weight (over your Slots, under Slots + 2), you're hindered, you take a -1.
When you make a move with way too much weight (Slots + 2 or over) you have a choice: drop an item and make the move at -1, or automatically fail as if you had rolled a 6-.
The Wizard has 3 or 4 Slots, the Fighter and Paladin have 7 or 8, everyone else is somewhere in the middle.
You can't get too carried away with Weight 0 items. GM's call, but in general more than your Strength score (not mod) in Weight 0 items counts as Weight 1.