Get a comprehensive understanding of Pennsylvania real estate purchase and sale agreements with our indepth overview and free template. A Pennsylvania residential purchase agreement establishes a legal arrangement between a buyer and a seller in a real estate transaction.The Consumer Guide is designed to help consumers better understand the major terms of the Standard Agreement for the Sale of Real Estate (Form ASR). A For Sale By Owner contract Pennsylvania must include: 1. The Purchase Price, 2. The standard agreement specifies details of the property including purchase price, buyer's responsibilities and much more. First, the buyer must present a valid offer, in writing, to the seller. Second, the seller must accept the buyer's offer to purchase the agreement.