A commercial purchase agreement is a legal real estate contract that transfers commercial property ownership from a seller to a buyer. A long form agreement for the purchase and sale of commercial real property in Illinois.Forms are state specific because real estate laws vary significantly from state to state. IICLE offers Illinois lawyers effective practice guidance and CLE credit in a variety of formats. The Seller shall have until. , 20___, to approve the. Create, commit to, and manage your agreements all in one platform with Docusign IAM. Electronically sign for free. This legal template is a simplified and seller-friendly contract for the purchase and sale of commercial property in the state of Illinois, under USA law. If you are venturing into the commercial real estate world, we can help you out.