Master Trader (Fallout)

Master Trader is a Fallout, Fallout 2, Fallout 3, Fallout Tactics, Fallout: The Board Game, and Lionheart perk.

Fallout, Fallout 2, Fallout Tactics
You have mastered one aspect of bartering - the ability to buy goods far cheaper than a normal person. With this Perk, you get a 25% discount when purchasing items from a store or another trader.

In Fallout, this perk adds the equivalent of 25 invisible skill points to the player's Barter skill when determining prices.

In Fallout 2, due to a change in the Barter formula, this perk subtracts 25 points from a barter modifier, which is then multiplied by the original price and the Barter skill modifier.

By default, the modifier starts at 100%, but Reaction modifiers can add 25 points, 0 points, or subtract 15 points at the same time, making the discount appear to vary from 20% (when there is a +25 point "negative reaction" modifier), to 25% (with "neutral reaction" modifier (0 points), up to 40% (with a -15 point "positive reaction" modifier).

Fallout 3
With this perk, the price of every item you buy from a vendor is reduced by 25%.

Fallout: The Board Game
It can be discarded to allow the player character to shop at their current location. They can buy and sell an unlimited number of items.

Lionheart
With this perk, you get a 25% discount when purchasing items from a store or trader, and you add 10 points to your Speech skill.