I've been a Costco member for in excess of 25+ years.
Like the company, however, went to a Gilbert, AZ Costco purchased a product that had an immediate $20 coupon discount. To my surprise, Costco charges sales tax on the higher price not the actual sales price. Went directly to Sam's Club, purchase same product at the discounted price and paid sales tax on the sales price.
So, if you purcase a car or large Costco Item, beware, they will change you sales tax on the higher price, so watch out, Costco/AZ state sales tax exceeds 10%+. This is over the top! I am sure Costco will blame the State of AZ, bull ***....all they have to do is the same and all other retailers do, publish the sales price and charge sales tax on the sales price!!!!
WELCOME TO ARIZONA THE TAX REPUBLICAN STATE!