Identify the parties involved in the transaction. 2. A purchase agreement is a type of contract that outlines terms and conditions related to the sale of goods.In this training, I'll discuss how to fill out a wholesaling contract in real estate. In a business sale, a letter of intent (LOI) is a buyeroriginated document through which the buyer expresses its intent to buy the subject business. A commercial real estate purchase agreement is a legal contract between the buyer and seller of a commercial property. STOCK PURCHASE AGREEMENT from ENERGY KING, INC. Filed with the Securities and Exchange Commission.