The school district is the biggest variable
Buford City Schools is an independent system that serves properties inside the incorporated city limits. If your parcel is in it, the county school levy does not apply to you — a different school millage does. School tax is typically the single largest component of a Georgia property tax bill, so this one distinction moves the total more than anything else on the page. Two comparable homes with Buford addresses, one inside the city and one just outside it, are not carrying comparable bills.