Pre-War money (Fallout 3)

Pre-War money can be found scattered through various places inside and outide of the capitol wasteland's structures and terrain. To date there is no known use for pre-war money except as a valuable commodity since it nets you anywhere between 10 and up caps and weighs nothing. Since it's weightless there's no reason why you shouldn't pick it up and sell it. It appears as a think pile of dollar bills held together by an elastic band. It's not confirmed whether the bills are hundreds, tens or fives. It's also unconfirmed why anybody would be willing to buy this since it's not actually a currency.