Vendors

Vendors (also called merchants or stores) allow the player to buy, sell, or trade goods in exchange for copper pands. Vendors can be found in towns and cities throughout Eora, and offer a wide variety of items, including consumables, weapons and armor.

In addition to general barter, many vendors also offer retraining of existing party members, recruitment of new party members, crew members (in Deadfire), and rooms to rest.

Stores
Stores are used to buy and sell items between the party and the vendor. Stores typically stock a collection of items that are re-stocked over time if depleted (by default every 12 hours of in-game time), alongside a select few items that may only be purchased once. Every item has a monetary value, which is summed in the transaction to determine how much you pay or receive. Quest items cannot be sold. Typically, items are sold to vendors at a depreciated value.

Stores will often have one or more nearby containers containing a subset of the items sold by the vendor. These are usually linked with the store inventory, taking from the container will result in the stolen items being removed from the store (and vice versa). This provides an alternate means of obtaining some of the unique items found in stores, without the need to resort to violence (and without the need for coin.)

Item values
In, all items have a base value (as shown on the wiki). When buying an item from a vendor, this value is multiplied by 1.5 (150%) to determine how much you owe. When selling an item to a vendor, this value is multiplied by 0.2 (20%) to determine how much you receive.

In, the base value of the item (shown as "shop value" on the wiki) is how much you will have to pay to purchase an item from a vendor. When selling an item to a vendor, the value is multiplied by 0.2 (20%) to determine how much you receive. This is rounded down (truncated) to the nearest integer.

Vendor rates
Vendors have set rates, a multiplier applied to the value of all items sold and bought by the vendor, as well as costs associated with renting rooms at inns. While the framework for it exists, vendors do not offer adjusted multipliers for goods that you sell to them, regardless of reputation.

Your reputation with the faction that a vendor represents is the primary source of value adjustments to items sold by the vendor, with a bad standing meaning added costs, and a good standing meaning reduced costs. If the vendor isn't associated with a faction, the default buy/sell rates are used. In addition, completing certain quests will earn you discounts in some stores.

Some vendors have fixed rates that do not change (e.g. permanently discounted).

In

 * With the "Unique Item Vendor" Berath's Blessing, receive a 50% discount at the Well-traveled Supplier in Port Maje Harbor.
 * Returning the gloves to Fessina during Velvet Glove, Brass Fist will give you a 5% discount at The Dark Cupboard in Periki's Overlook.
 * Completing The Shipwright's Plight will give you a 10% discount at The Shipyard (port vendor) in Neketaka.
 * Completing The Cornett's Call will give you a 10% discount at Ernezzo's Supplies in Delver's Row.
 * Eliminating Ernezzo for The Spindle Man during Harsh Medicine will give you a 10% discount at Spindle Man's Store.
 * Getting rid of Galian peacefully during The Better Man will give you a 15% discount at Kraken's Eye in Port Maje Harbor.
 * Taqua's Fish Emporium in Sayuka has a permanent 15% discount.
 * The apothecary Tama Watua offers a permanent 15% discount at his store Tama's Oddities, in Outcast's Respite in Rikuhu's Maw.
 * On the world map, the following unmarked locations give a permanent 50% discount to goods sold:
 * "Fisherman's Hut" at 25° 40' S 39° 40' E (north of Maje Island).
 * "Huana Koīki Farm" at 5° 4' 48° 39' E (in the very northeast corner of the map, near Ofecchia Channel).
 * "Huana Koīki Farm" at 38° 15' S 37° 19' E (southwest island of the Kângati Islands).
 * "Vailian Mill" at 37° 7' S 35° 35' E (far south of Fort Deadlight).
 * Caretta, Cook Corrin, Winge, and Neale in the Temple of Toamowhai will give the player a discount in their respective stores depending on their reputation with either of the Seeker, Slayer, and Survivor factions, however the logic for this is currently broken:
 * 5% discount to players with a Good 1 reputation.
 * 10% discount to players with a Good 2 reputation.
 * 15% discount to players with a Good 3 reputation.
 * After completing An Honored Guest, talk to Harbinger Karlódh and say "Yes, I am the destroyer. The very hungry destroyer. Feed me fish." to receive a 10% discount at her store, the Snowmelt Fishery.