The agreement must have a start and end date. A one time showing agreement can give an agent permission to enter the sale, it does not conform to contracts we accept for entry.The purchase agreement attached here is a standard purchase agreement between the buyer and seller, for properties located in Ohio. 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. A For Sale By Owner contract Ohio must include: 1. The Purchase Price, 2. They will contact the seller or the listing agent and meet at a specific time. This agreement is contingent upon Purchaser obtaining approval of a. Conventional,. However, Buyer Agents are not required to provide the Listing Agent with a copy of the Buyer Representation Agreement to schedule a showing. Four (4) essential elements ensure your agreement is valid and legally binding.