Marietta the city, Cobb the county
The seat stands in for the county on this page because the work does. An engagement that starts with a Marietta attorney routinely concerns a house in Smyrna, Kennesaw, Powder Springs, Austell, or Mableton, and I take all of it. Each of those cities is its own pricing environment: Smyrna's rebuilt-and-infilled streets near the Battery trade nothing like Powder Springs acreage, and Mableton, newly incorporated and enormous, contains several markets by itself.
The point of saying so is the same point the whole page makes. Cobb rewards specificity. The county-level averages that automated tools lean on are blended from submarkets that have little to do with each other, and a defensible report starts by ignoring them.