What makes South Carolina different
The money works the other way round. The statutory band for speeding is genuinely narrow — narrower than almost any state in this dataset — and it is then multiplied several times over by state and county assessments before a driver pays anything. The figure in the statute and the figure on the ticket are not close.
Both facts push in the same direction: the published numbers understate the consequence, and the useful question in South Carolina is what the total looks like after the assessments and what the record looks like after the halving.