Karl (Fallout 3)

Karl is a 37-year old member of the Family in Fallout 3. Karl doesn't believe in Vance's teachings but plays the part to have his store in Meresti.

Store
His store is open from approx. 2 pm to 8 pm (unlike other stores, open approx. 8 am to 6 pm). He sometimes sells Blood Packs at the regular "junk item" price (base value 5), which can then be sold nearby to Vance for 15 caps (not subject to Barter). This is only possible if you have brokered a deal with Vance and Evan King of Arefu.

Karl also has one of the biggest merchant inventories in Capital Wasteland. Just near his desk is a freezer full of Scrap Metal. He can also sell upwards of twenty pieces of Scrap Metal the first time the player meets him.

Some of the noteable items he may sell include 2 Stealth Boys, an Advanced Radiation Suit, a Nuka-Cola Truck and a fair amount of Microfusion Cells.

Bugs.
karls store inventory instantly refills stimpaks after you buy them allowing the player to obtain unlimited stimpaks so long as you pay for them.(PS3 confirmed.)