A master purchase agreement is a legally binding contract between buyer and seller, and typically relates to buying and selling goods rather than services. A land sales agreement is a legal contract between a seller and a buyer that is used to purchase real estate and outline the terms of the transaction., in full in legal tender to Seller at Closing. Sale of Goods Agreement (Pro-Buyer, Short Form) (TX). (Pro-Buyer) (5-541-6567). "We fill in the terms the buyer is trying to accomplish closing date, amount of the offer, down payment, financing, that sort of thing. Purchasers at Texas state agencies are required to purchase from the Contract Sources if contract items meet their specifications. Tract included in the Land is located is acquired;.