Yes, the sales price includes the sales tax. The sales price of heavy equipment is defined in Section 23.1241(a)(7), Tax Code, as “total amount of money paid or to be paid to a dealer for the purchase of an item of heavy equipment” or “for a lease or rental with an option to purchase, the total amount of the lease or rental payments plus any final consideration, excluding interest.” The sales price includes the sales tax since it is part of the “money paid or to be paid to a dealer” for the purchase of the heavy equipment.