S.C. Code Ann. § 12-36-130 — "Sales price"

"Sales price" means the total amount for which tangible personal property is sold, without any deduction for the cost of the property sold, the cost of the materials used, labor or service cost, interest paid, losses, or any other expenses.
(1) The term includes:
(a) any services or transportation costs that are a part of the sale, whether paid in money or otherwise;
(b) any manufacturers or importers excise tax imposed by the United States; and
(c) the proceeds from the sale of property sold on consignment by the taxpayer, including property sold through a marketplace by a marketplace facilitator.
(2) The term does not include:
(a) a cash discount allowed and taken on the sale;
(b) an amount charged for property, which is returned by the purchaser, and the full amount is refunded in cash or by credit;
(c) the value allowed for secondhand property transferred to the vendor in partial payment; and
(d) the amount of any tax imposed by the United States with respect to retail sales, whether imposed upon the retailer or consumer, except for manufacturers or importers excise taxes.
For purposes of the sale of an "audiovisual master" as defined in Section 12-36-2120(55), sales price is the total amount for which the audiovisual master is sold, including charges for any services that go into its fabrication, manufacture, or delivery that are a part of the sale valued in money whether paid in money, or otherwise, and includes any amount for which credit is given to the purchaser by the seller without any deduction from it on account of the cost of the property sold, the cost of materials used, labor or service costs, interest charged, losses, or any other expenses whatsoever.
The term "sales price" as defined in this section, also does not include the sales price, not including tax, of property on sales which are actually charged off as bad debts or uncollectible accounts for state income tax purposes. A taxpayer who pays the tax on the unpaid balance of an account which has been found to be worthless and is actually charged off for state income tax purposes may take a deduction for the sales price charged off as a bad debt or uncollectible account on a return filed pursuant to this chapter, except that if an amount charged off is later paid in whole or in part to the taxpayer, the amount paid must be included in the first return filed after the collection and the tax paid. The deduction allowed by this paragraph must be taken within one year of the month the amount was determined to be a bad debt or uncollectible account.