Theoretically, you could write an offer on a restaurant napkin but nearly all Arizona home purchase offers are written on pre-made contract forms. You are legally bound to honor the agreement.An Arizona residential purchase agreement is a legal document outlining the terms and conditions for a buyer's purchase of residential property from a seller. An offer is just a contract with only buyer signature on it. The following is a checklist of helpful hints for consumers to help avoid some of the pitfalls of purchasing a new or used home, or raw, undeveloped land. Get a comprehensive understanding of Arizona real estate purchase and sale agreements with our indepth overview and free template. Once you've found the home you wish to purchase, I'll guide you through making an effective offer based on property and market conditions. Customer: What form is needed to make a cash offer on a house in arizona. The form for the buyers realtor. An Arizona residential purchase agreement is a legally binding document that outlines the terms and conditions for the sale of residential property.