When I lived on Capitol Hill I frequented Eastern Market. Every weekend was overflowing with amazing local artisans and a good variety of produce. However, I never found that the produce was really all that affordable. I typically only bought a few fresh food items. I think I enjoyed the live music, the ambiance of all the different vendors and sampling different foods more than actually buying food.
In fact, every farmers' market that I've been to in the Washington, D.C. area is really not that cheap. When I lived downtown in Penn Quarter I stopped by the Thursday farmers' market a few times to see what was on display. I remember seeing a medium size bag of mushrooms for $7. That's absurd. The Penn Quarter farmers' market is also rather limited, with maybe a dozen different vendors.
The Thursday Ballston, Virginia farmers' market is also not that impressive. Come Thursday I always find my way strolling through the market to see what's new and available, but never end up buying anything. (I work in Arlington so it's easy to pop over to the market.) Unfortunately, a bushel of strawberries, blackberries or blueberries are far more expensive than the local grocery store.
This puts me in a difficult situation. While I prefer supporting local business that usually don't farm with pesticides, unfortunately in most cases the big super market is more affordable.
When I lived in New Hampshire, I found myself stopping by the local farm stand on the side of the road all the time. It was part of my regular routine. My favorite was picking out fresh corn on the cob, a true summer-time delicacy.
I don't know if farmers' markets that are located in the city or in the suburbs are more expensive because they have to travel farther or that local farmers know they can charge more because of demand from city-slickers.
Whatever the reason, I wish it wasn't the case. Not everyone living in or around a city can afford high priced fresh produce. I wish that trying to eat healthy and supporting local didn't come at such a cost. It's far cheaper to eat a McDonald's hamburger and be full than it is to eat some fresh vegetables and still be hungry.
In any case, I'm going to continue my search in the northern Virginia area for a good, affordable farmers' market. Localharvest.org has a great listing of farmers' markets based on your location.
I've read through some reviews on Yelp about the Saturday morning (8 a.m. to noon) Arlington (Courthouse) farmers' market and it looks like a winner. I'm going to check it out this weekend and write up a review later.