This agreement is contingent upon Purchaser obtaining approval of a. Conventional,. The buyer will use the agreement to make an offer, listing the purchase price, expiration date, and more.A purchase and sale agreement is a contract between a buyer and seller for transacting a property in exchange for a specific price. The offer to purchase real estate form comes in various forms in New York, and can vary based on the brokerage firm. A product sales agreement is a contract that states the terms of sale for any services or goods that are sold to a third party.