Master real estate purchase agreements for simple, friendly transactions. A land sales agreement is a legal contract between a seller and a buyer that is used to purchase real estate and outline the terms of the transaction.Learn about real estate purchase agreements and review tips for agents to protect buyers with well-prepared real estate contracts and negotiations. Assignment and Assumption of Real Property Leases, the Master Lease Agreement, the. The Buyer has agreed to buy and the Seller has agreed to sell the Shares and the Assets, which represent the Business, on the terms set out in this Agreement. Mike Grauwelman provided an outline of the agreement between the Land Bank, KHN, and the City of.