When it comes to filling out a real estate purchase agreement, several key players are involved: buyers, sellers, real estate agents, and attorneys. Every purchase agreement should include buyer and seller names, transaction date, the item being purchased, and the purchase price and terms.A written real estate purchase agreement is essential when buying a home. It benefits the buyer and the seller and acts as a legally binding agreement. Step 1 – Fill Out the Buyer and Seller Information. 1. Seller. Write down the seller's full name.