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. Ready to put a bid on your new property?Download FortuneBuilders' free real estate offer letter template so your proposal stands out. 1. Get the right form. First, you will be needing the appropriate form for your state and type of purchase. House Offer Letter Templates. A Florida residential purchase agreement outlines the terms of a transaction between the seller of residential property and the buyer. Getting ready to write an offer for a house? In this video, I show you how to fill out the As-Is contract to purchase a home. An Offer to Purchase Real Estate sets out the terms of a proposed real estate deal.