That is a tricky question. Early on the trail, people have to buy a lot of stuff due to suddenly understanding why a 3 lb tent is $ 300 better than a 6 lb tent when you are the one schlepping it up and down the hills. Winton has a lot of this business, seeing as how the trail passes straight through his building.
Helen, GA could stand to have an outfitter, although, the one there closed up shop this year, must be a reason why it didn’t survive.
My suggestion would be to ignore the thru hiker phoenomenon when seeking a business location, and IF you locate a town suitable to support an outfitter, AND it is near enough to the trail to secure some thru hiker business, then you can count that brief influx of business as gravy, rather than counting on it as your meat and potatoes.
Just my 2 cents though
Tabasco