You're right, it's not like a sales tax.  It's much worse.  "Experts generally agree that Hawaii has the broadest sales tax in the United States, taxing many products multiple times and, by one estimate, ultimately taxing 99.21 percent of the state’s personal income. This base is far wider than the national median, where the sales tax base applies to 34.46 percent of personal income,” http://www.bizjournals.com/pacific/blog/2013/08/tax-foundations-ranking-for-hawaiis.html   "If you did an apples-to-apples comparison, factoring out state sales tax bases, Hawaii has a sales tax rate equivalent to over 11%. The gross receipts tax format allows for a low rate but it cannot hide the fact that Hawaii’s sales tax is one of the most economically burdensome in the country." https://taxfoundation.org/hawaiis-gross-receipts-tax-economically-damaging-despite-low-rate/