I'm gonna break down all the terms and conditions so you can understand what it means and we're gonna fill that out so you can have a real-life example of it. 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. Step 1 – Fill Out the Buyer and Seller Information. 1. Seller. Write down the seller's full name. Free Real Estate Purchase Agreement. Answer a few simple questions.