(a) Except as provided by Subsection (b), a supplier may not discriminate, directly or indirectly, in the price among different dealers with respect to a purchase of equipment or a repair part of like grade and quality and identical brand, where the effect of such discrimination may be to:
(1) substantially lessen competition;
(2) tend to create a monopoly in any line of commerce; or
(3) injure, destroy, or prevent competition with any dealer who either grants or knowingly receives the benefit of such discrimination.
(b) A supplier may charge a different price among dealers for purchases described by Subsection (a) if:
(1) the price difference is due to differences in the cost of manufacture, sale, or delivery of the equipment or repair part;
(2) the supplier can show that the lower price was made in good faith to meet an equally low price of a competitor; or
(3) the price difference is related to the volume of equipment purchased by dealers or market share obtained by dealers.