I recently visited Thai Arroy, 1019 Light Street, for lunch with my cousin. This small, mural-wallpapered restaurant is in Federal Hill, on the Charm City Circulator Orange Route. (The restaurant also has a location in Virginia Beach, which sounds like potential beach vacation salvation.) Thai Arroy offers an affordable lunch special: $7 for a large main veggie dish with side salad or soup.
For the main course, the menu instructs you to pick a protein, then a style. So we had mock duck in Nam Prik Pao and tofu in Med Ma Maung. The mock duck dish is also charmingly called, "Mr. Green," and had lots of green beans and some impressively large, albeit slightly over-cooked broccoli. The spicy tofu dish had hot peppers, cashews, carrots, scallions, and onions. The brown rice was an extra dollar than the white rice but well worth it.
For the sides, we tried both the salad and the soup. I'd recommend the latter, as the salad was bland with iceberg lettuce and a typical peanut dressing. On the other hand, the delicious tom kha soup was rich and mushroomy. It did cost an extra dollar more than the veggie and tofu soups listed on the standard lunch special. (Maybe it's a coconut milk tax?) We also had sweet and refreshing young coconut drinks, not pictured here. Overall, this lunch deal seems like a winner, just be prepared for some surcharges.