An Illinois purchase agreement is a standard contract for selling real estate from one party to another. ACCEPTANCE DATE: ("Acceptance Date").SELLER'S INFORMATION: Seller's Signature: Seller's Name (print):. A real estate purchase agreement is a legal contract. A good agent repping a buyer doesn't just write the offer, either. The agreement is essential in guiding the process from initial offer to closing, making it one of the most important documents in any real estate transaction. Purchase Offer and Counteroffer Forms. The price; Time-sensitive terms (like appraisal and inspection); Property details; A general timeframe for transitioning ownership. Sellers are required to complete a property disclosure statement in which they respond to questions about the material condition of their home. The Chicago Zoning Map Tool is a resource to identify City-owned lots and property zoning.