In a transaction involving a vessel, an outboard motor, or a trailer that is treated as a vessel that does not involve the use of one of these forms, the term means an amount of money that is equivalent, or substantially equivalent, to the amount that would appear as "sales price" on the Application for Texas Certificate of Number/Title for Boat/Seller, Donor or Trader's Affidavit, the Application for Texas Certificate of Title for an Outboard Motor/Seller, Donor or Trader's Affidavit, or the Application for Texas Certificate of Title if one of these forms were involved.
The term "vessel" also includes trailers that are treated as vessels as defined in this section.
Tex. Tax Code § 23.124