That's why for hair care, I like to go to Japanese operated places. They have never failed me and always write the the price and their break-downs on paper to show you for approval before they start. Not to mention they place a towel on your face when they wash your hair and the entire store saying good bye and thank you! Best of all, these little extras don't cost extra!
It's not cheating. Some shops do charge taxes according to the pre-sale price. Costco is one of those. But it states it clearly on their flyers and coupons.