An agreement to sell real estate, or a purchase agreement, is a legally enforceable document that specifies the terms of a real estate transaction. ADRE has moved to appointment-only for in-person assistance.If you would like in-person assistance, please reach out using our Message Center. First, include the property address as well as its legal description (found on the deed). Then go into detail about what is included or excluded from the sale. The document is a sample residential real estate purchase contract for Arizona. A purchase and sale agreement is a contract between a buyer and seller for transacting a property in exchange for a specific price.