Check out this section for sample language for many different situations. An Offer to Purchase Real Estate sets out the terms of a proposed real estate deal.Create yours now with our free form. Selling a house without a realtor involves preparing prelisting, listing, disclosure, negotiation, and closing paperwork. Legal help can be beneficial. A For Sale By Owner contract Illinois must include: 1. The Purchase Price, 2. Today's video is focusing on the paperwork specifically the assignment agreement between you and your cash buyer. Mainstreet has created an addendum to Multi-Board Residential Real Estate Contract 7.0 in which the seller may agree to pay the buyer's brokerage compensation. Mainstreet has created an addendum to Multi-Board Residential Real Estate Contract 7.0 in which the seller may agree to pay the buyer's brokerage compensation.