Haw. Rev. Stat. § 231-98: Tax avoidance price fixing.

It shall be unlawful for any person to sell, offer to sell, or otherwise convey more than one price for any business to be transacted when the lower price is offered if the transaction is paid for in cash. It shall not be an offense under this section if a business charges a higher price for legitimate business purposes, such as for the purpose of recovering any charges assessed the business, including for facilitating electronic payment. Any person who violates this section shall be subject to a fine not to exceed $2,000; provided that if the person is a cash-based business, the fine shall not exceed $3,000.