Add the names, contact details, and addresses of the required parties. List property details, like the legal description and registered address.In this ultimate guide, we will unravel the mysterious world of buyout agreements and show you stepbystep how to navigate them like a pro. An Illinois purchase agreement is a standard contract for selling real estate from one party to another. A buyout agreement is a binding contract between business partners that establishes the buyout details of one partner exiting the partnership. A purchase and sale agreement is a contract between a buyer and seller for transacting a property in exchange for a specific price.