In some of the nicest areas of Baltimore (which it sounds like you're looking for), a single family home will only be around 200k-400k which is probably less than it'll run you in Northern Virginia. These nice areas generally have high taxes, but you'll usually get quality tenants. Hampden, Charles Village, Fed Hill, Fells Point, Inner Harbor, and Canton are a few neighborhoods that are A neighborhoods, but have plenty of renters. You can also look in areas like Roland Park, which is also really nice, but you won't find many renters there, as that has a very high ownership rate. Baltimore is generally block to block, but in those neighborhoods, you'll be pretty safe. I believe most of these neighborhoods have an additional tax for being the nicest neighborhoods in Baltimore, so that will eat into your cash flow, but generally Baltimore has great cash flow. However, you'll be hard pressed to see much (or any) appreciation.
There are also plenty of neighborhoods that are a grade below that are still excellent investments. I just say this because these neighborhoods I mentioned already are most certainly not the only places one should invest, but they will be a bit safer.
You can also consider some of the surrounding Baltimore county, but that is out of my realm of knowledge. Generally, those are investments with lower cash flow, and more competition, but they're safer investments. However, that's just a massive generalization, and obviously varies.