I live in NW DC. Where has good prices on beer? I have a car and can drive a bit if it saves me money. I'm not looking for obscure stuff, just a case of Heineken or something.
Rodman's on Wisconsin Avenue - good prices, sales on basic domestics and imports. Good selection of American micros and foreign beers if the mood strikes.
The liquor store on P St. in Dupont Circle has pretty good prices (from what I can tell) but even better an excellent choices. Often Thursday-Saturday they have different tastings. People there are very helpful and friendly.