Edit, sign, and share fl purchase agreement online. No need to install software, just go to DocHub, and sign up instantly and for free.A Florida residential purchase agreement outlines the terms of a transaction between the seller of residential property and the buyer. Selling your home FSBO? Use a normal real estate purchase agreement, and just indicate as one of the conditions that you are buying the property subject to the existing mortgage. You might want to consider hiring a transactional agent, a real estate professional who facilitates paperwork for both the seller and the buyer.