Purchase and Sale Agreement. A purchase and sale agreement is a contract between a buyer and seller for transacting a property in exchange for a specific price.The Columbus REALTORS® purchase contract shall be printed in 11-point Arial font, and all deviations in the standard form must be. The property and improvements which the Seller is agreeing to sell and which the Purchaser is agreeing to purchase is known as. A For Sale By Owner contract Ohio must include: 1. The Purchase Price, 2.