A purchase and sale agreement is a contract between a buyer and seller for transacting a property in exchange for a specific price. PAR's Buyer Agency Contract includes all of the legallyrequired language and allows for a buyer's broker fee to be structured in several ways.Streamline your real estate transactions in Pennsylvania with our customizable purchase agreement. Ensure legal compliance and purchase or sell properties. A Pennsylvania residential purchase and sale agreement allows a prospective buyer to purchase residential real estate from a seller. This document is a legally binding contract for the purchase of a property located in Philadelphia, Pennsylvania. A Pennsylvania purchase agreement creates a secured contract for a residential property transaction. Step 1 – Fill Out the Buyer and Seller Information. 1. Seller.