Value
Every item has a base value. Quality multiplies it: x1.5 for Uncommon, x2.2 for Rare, x3.5 for Epic and x6 for Legendary. The value on an item's tooltip already includes its quality.
An item with no value cannot be sold at all: "You cannot sell this item."
Selling
A shop pays its own percentage of the value, rounded down for each item. There is no tax and no haggling.
- Most shops buy anything. The rest only buy what they stock themselves.
- What you sell goes on that shop's shelf, where anyone can buy it at the shop's price. Gear keeps its quality and modifiers when it changes hands this way.
Buying
A shop charges its multiple of the value, rounded up. Everything a shop stocks is Common; the only better gear on a shelf is gear somebody sold there.
Stock is limited. Each shop refills to its usual amounts on its own timer.
The shops
Every shop you can walk into, with what it pays and charges and the price of one Iron Sword at each:
| Shop | Pays you | Charges you | Sell one | Buy one | Buys anything | Restocks every |
|---|---|---|---|---|---|---|
| Fishing Store | 100% of value | x12 value | 83 | 996 | Only what it stocks | 5s |
| General Store | 100% of value | x15 value | 83 | 1,245 | Yes | 30s |
| Peddler's Shop | 60% of value | x8 value | 49 | 664 | Yes | 1m 15s |
| Legs Shop | 55% of value | x10 value | 45 | 830 | Yes | 1m |
| Bread Shoppe | 45% of value | x8 value | 37 | 664 | Yes | 45s |
| Weird Shop | 30% of value | x8 value | 24 | 664 | Yes | 50s |
Prices for one Common 
Iron Sword, value 83.
The gap is the point: buying an item and selling it back always loses money. Shops are for getting rid of what you gathered and made, and for buying what you cannot make yet.
After a death
Adon is a shop of sorts too. Buying your own things back from the death container costs half their value, rounded up, after three free picks. See death and recovery.