S.C. Code Ann. § 39-41-255: Retail outlets shall post self-service pump gasoline prices.

Every retail motor fuel outlet shall post in a conspicuous place the self-service pump price for each type of gasoline it has available; provided, that such posted price must include either the cash or the credit price but need not include both such prices. The manner in which the prices are posted must not conflict with any state or local laws or ordinances that regulate the size, use, or placement of billboards or signs. The posting on the pump price mechanism of the price of the type of gasoline available at that pump shall satisfy the requirement of this section.