A purchase agreement is a legal contract between a buyer and a seller. I'm gonna break down all the terms and conditions so you can understand what it means and we're gonna fill that out so you can have a real-life example of it.How to fill out the Real Estate Purchase Agreement Commercial Agricultural? With our free Sales Agreement form, you'll be ready to print or download your contract in no time. PandaDoc's free simple purchase agreement template lets you create legally binding contracts for small business purchases and deals.