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.Save time and money with PandaDoc. Learn about real estate purchase agreements and review tips for agents to protect buyers with well-prepared real estate contracts and negotiations. Contracting for Supplies and Services - Purchasing (UIC) The Contract for Procurement of Supplies and Services is the preferred template. An Illinois real estate contract is a legally binding document that outlines the terms and conditions of a real estate transaction between a buyer and a seller. Procurement Forms, Quotes, Bids, and RFPs, Standard Contract FAQs, Purchasing Related Forms and Documents, Contract Related Forms and Documents. 23 incorporated or used in the accepted Deliverables. All potential contractors shall be registered in the Illinois Procurement Gateway vendor portal prior to contract execution.