The most reliable way to compare across counties is to normalize by price per acre rather than comparing total listing prices, since parcel sizes vary too much for raw prices to mean much on their own.
From there, match for the factors that actually drive value in each area:
- Similar access, paved road frontage versus dirt or landlocked
- Similar intended use, recreational, buildable, agricultural
- Similar proximity to a town center or growth corridor
Even after normalizing for price per acre and use, a few county specific factors can still explain why similar looking land prices differently across a line on a map:
- Tax rates: millage rates and any agricultural use classifications vary by county and affect the real cost of holding land there.
- Zoning flexibility: some counties allow more by right uses or easier subdivision than others, which affects what a parcel can become.
- Growth trajectory: a county actively growing toward a metro area tends to command a premium over a similar but more static county, even if today's land looks comparable.
Put together, a fair comparison isn't just one county's average price per acre against another's. It's matching comparable parcels within each county on access and use, then layering in the county level context, tax structure, zoning, growth direction, that explains any remaining gap. Skipping that second step is where most cross county price comparisons go wrong.