Final answer:
A clause that guarantees a buyer the lowest price in a sales contract is known as a "most favored customer" or "best price" clause. Minimum price agreements are illegal as they restrict competition, unlike best price clauses which are permissible. Sellers may also offer warranties or service contracts for large purchases.
Step-by-step explanation:
The clause in question within a sales contract that guarantees a buyer the lowest price that the seller offers is known as a "most favored customer" or "best price" clause. This clause ensures that a buyer receives as favorable prices, terms, and conditions as any other customer. In comparison to minimum price agreements, which are illegal due to their restrictive impact on competition among resellers, offering a best price guarantee is a legitimate and lawful practice in commerce.
Moreover, sellers may provide warranties or service contracts, the latter of which often applies to substantial purchases like vehicles or appliances, where a service agreement results in the seller undertaking to repair any issues over a specific period in exchange for an additional fee from the buyer.