I grew up right on the line between southern PA and northern MD. My husband and I are both from the area.
The farther east you go, the horsier it gets. I literally grew up in horse heaven (Chester County, PA- Oxford to be specific). We left because a) we didn’t appreciate our hometown in our youth, and b) land values were so high at the time it didn’t look like we’d ever afford a farm.
Ironically, we moved to TN shortly before housing boomed here. While the cost of living is still a bit lower, property values in our area are now pretty much the same as Oxford!
I’ve hit my breaking point with the limited horse scene here. I love Nashville, I love the weather, but I can’t deal with back country, crappy horse services any longer. I’d go back home in a heartbeat if the opportunity came up!
With all that said, definitely investigate southern Chester County/southern Lancaster County, PA and Cecil County, MD. Extremely horse-friendly and relatively affordable depending on the location! The closer you get towards Philly/Baltimore, the more expensive it will get.