Barter

Barter is a skill in Fallout, Fallout 2, and Fallout Tactics: Brotherhood of Steel.

Trading and trade-related tasks. The ability to get better prices you sell, and lower prices for items you buy.Your reputation and reaction from the NPC will modify how they deal with you. If you have a good reaction with the NPC trader, you will get a better deal. If he doesn’t like you, you will pay for it – literally. Your Barter skill, however, is the primary factor, along with the Barter skill of the NPC. Initial Level: Starting Barter skill is equal to 20% + (2% x Charisma). Average characters will have a 30% skill.

Having the "Master Trader"-perk will give you 10% bonus to this, although. The "Good Natured"-trait will give you additional 25% on the Barter skill.

This information is 'NOT CANON' as long as i don't find the source for this information. It is taken from the Fallout PnP game: ''Barter skill works like this: the character compares his or her Barter skill to the merchant's. Whoever has the higher Barter skill has the advantage. Take the higher skill number and deduct the lower skill, and then add that percentage to the value of all that person's goods. If the character has a Barter skill of 50%, and is dealing with a tribal leader whose Barter skill is 25%, the character's goods gain a 25% value. A knife worth 100 would then be worth 125.''