Items with the Fortify Barter property are extremely rare and their effects stack additively. Prices are also affected by one's Speech skill level, as well as relevant perks. Stacking bartering items and having a decently high speech will grant extraordinary discounts when purchasing items and greater returns when selling items.
The bonus cap for markup is 105%. This can be achieved with 100 Speech and 50% barter. Items worth 100 gold can now be purchased from merchants for 105 gold.
The bonus cap for buying is 100%. This can be achieved with 100 Speech and 50% barter. Items worth 100 gold can now be sold to merchants for 100 gold.
Any number above either bonus cap from any source will not make a further difference to the price of an item.
A good way to boost bartering is to enchant any necklace with 29% Fortify Barter, equip a headpiece and a piece of armor with the Fortify Barter effect (see full list below), and visit a shrine of Zenithar. Speech over 100 will not reduce prices but is worth more than Fortify Barter, so one may want the blessing of Dibella instead of Zenithar depending on the player's level.
Amulets are the only items that can be enchanted with this effect at an Arcane Enchanter. For this reason, it is strongly advised that any other types of apparel with the Fortify Barter effect are not to be discarded unless the player locates an item in the same slot that is superior or equal to their current item. Apart from enchantments, potions, and the blessing, the only other way to fortify barter is through speech perks.
- Standard Enchanted Amulet: 10% - 29%
- Cicero's Clothes: 20%
- Guild Master's Hood: 20%
- Clavicus Vile's Masque: 20% (and +10 Speech)
- Volsung: 20%
- Jester's Clothes: 12%
- Amulet of Zenithar: 10%
- Thieves Guild Hood: 10% (can optionally be upgraded to 15%, after completing the Thieves Guild mission Scoundrel's Folly.)
- Blackguard's Hood: 25%
- Fortify Barter Necklaces may be purchased from general merchants such as Belethor in Whiterun.