Super Food Mart
4705 Raleigh Rd
Temple Hills, MD 20748
They have the best prices by far, you'll find quite the selection as well. They got herbs starting at even $5. Who can beat that and they dont' charge crazy amounts either, very reasonable price.
I live in Arlington so it's not too bad, but from Leesburg it will be an hour drive at least. It's worth it if you go there and make a purchase for a week.