A Texas Business Purchase Agreement will help transfer business ownership and outline the terms of the sale. A retail installment sale is a transaction between you and a dealer to purchase a vehicle where, you agree to pay the dealer over time.A publication to assist county Tax Assessor-Collectors with collection, remittance and regulations for Texas Motor Vehicle Sales and Use Tax. Before an offering or sale of a business opportunity in. Texas, the principal seller must register the business opportunity with the secretary of state. Tex.