Purchase and Sales Agreements - Chicago Business Lawyer. A real estate purchase agreement is a legally binding contract that establishes the terms between a buyer and a seller for the transfer of property.In this ultimate guide, we will unravel the mysterious world of buyout agreements and show you stepbystep how to navigate them like a pro. The two primary types of buy-sell agreements are cross purchase and redemption agreements, each with its unique structure and implications. An LLC buyout agreement template provides a framework for the legal paperwork that makes up an LLC buyout agreement. Simply put, a buy-sell agreement governs what happens to the business when one of the partners decides to exit.