I'm a little late to this thread but wanted to share insight on buying smaller acreage.
In some regions the taxing authorities will consider the first buildable acre to be the homesite and tax it at a much higher rate than for the remaining acreage. This rate captures the local govt's potential costs for providing services such as policing, schools, trash collection/dumps, and more to the purchaser.
Then the surrounding yard lot or pasture or woodland may be assigned various assessment rates based on perk-ability, agricultural suitability, and recreational opportunities (e.g. large creeks), as well as general proximity to either desirable (e.g. National Forest) or undesirable (e.g. quarries) features.
If you can demonstrate to the assessment office that a given property is only useful for, say, timbering or hunting, then they may wave the surcharge for the homesite assessment. Mitigating factors might include wetlands, steep or rocky terrain, or insufficient room to put in a septic field.