S.C. Code Ann. § 12-36-100: "Sale" and "purchase".

"Sale" and "purchase" mean any transfer, exchange, or barter, conditional or otherwise, of tangible personal property for a consideration including:

(1) a transaction in which possession of tangible personal property is transferred but the seller retains title as security for payment, including installment and credit sales;

(2) a rental, lease, or other form of agreement;

(3) a license to use or consume; and

(4) a transfer of title or possession, or both.