If Eastern Market feels like Bishkek City or the produce stalls at a bazaar, the market off Florida Avenue felt like the container section. It's optimistically called DC Farmers Market in some places, but I think Florida Avenue Market is a better name. Most of it is wholesale, but there are a reasonable number of places that are retail too. If you're looking for something you can't find elsewhere, I think this is a good place to try. There really is a wide variety of stuff tucked away if you're willing to poke around.
I was a little closer to the edge of my comfort level here that I usually am. But I'll definitely go back on my own again.