A payment plan agreement outlines an installment plan to repay an outstanding balance over a specified time frame. A purchase and sale agreement is a contract between a buyer and seller for transacting a property in exchange for a specific price.Fill Online, Printable, Fillable, Blank ILLINOIS RESIDENTIAL PURCHASE AGREEMENT Form. Residential Real Estate Purchase and Sale Contract. Download our free blank purchase agreement template in Word or PDF format: sample real estate purchase agreement template. Illinois Free Payment Plan Agreement Template. Use our Payment Plan Agreement to set up an installment plan between a lender and a borrower. A purchase agreement is a form used for making an offer on a home. It contains a set of conditions and contingencies that are presented to the seller of a home. SELLER agrees to provide and pay for an owner's title insurance policy in the amount of the Purchase Price insuring marketable fee simple title in.