A Pennsylvania residential purchase agreement establishes a legal arrangement between a buyer and a seller in a real estate transaction. A Pennsylvania purchase agreement creates a secured contract for a residential property 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 Pennsylvania residential purchase and sale agreement allows a prospective buyer to purchase residential real estate from a seller. Looking for a Pennsylvania real estate purchase agreement template? Download this free version today. 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.