Focus on three things: State your intentions, show that you have the financial means to make the purchase and make a personal appeal to the seller. The most important letter you'll submit to a home seller is the one you'll get from your lender stating that you are preapproved for a mortgage.An Offer to Purchase Real Estate sets out the terms of a proposed real estate deal. Create yours now with our free form. Craft a winning house offer letter with our customizable template and tips. 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 experienced Realtor is going to help you submit an offer that is neatly written, clear, concise, and completed thoroughly. Make your opener as personal as possible. Craft a winning house offer letter with our customizable template and tips. A laundry list of concessions can signal a highmaintenance buyer that will struggle to follow through with negotiations to complete the sale.