A master purchase agreement is a legally binding contract between buyer and seller, and typically relates to buying and selling goods rather than services. The standard agreement specifies details of the property including purchase price, buyer's responsibilities and much more.A Pennsylvania real estate contract is an agreement made when a buyer makes an offer to purchase a property from a seller. A purchase agreement (PA) is a written agreement between a buyer and seller to purchase and sell real estate. This is going to be how to fill out the agreement of sale for pennsylvania. A purchase agreement (PA) is a written agreement between a buyer and seller to purchase and sell real estate. The standard agreement specifies details of the property including purchase price, buyer's responsibilities and much more. Sellers are required to provide the filled-out form to buyers before each signs the purchase agreement. Rhode Island Real Estate Forms. Before you determine your MAO, let's look at how to lock in that property.