… should be buying gas, according to this map of D.C.-area gas prices. The lowest, in Maryland, are about $3.70 per gallon of regular gas. (The D.C. average is more than $4, but some stations are at or above $5).Larger symbols on this map, made with ArcGIS, represent higher prices: 

Here’s an interactive version: 

Source: washingtondcgasprices.com | Map shapefiles | Data