When I was in St. Petersburg with my mom, I attempted several times to go into the “Natives” line to acquire tickets for museums, parks, and shows. While my native Russian is now heavily accented, I figured I could manage a polite “two tickets please” without giving myself away. My mom laughed as I failed and failed. It was not my pronunciation that was at fault, but my American manners.
“Why are you saying please?” My mom asked. “She is giving you a ticket and you are giving her money. What else do you owe her?”
Of course, this form of price discrimination, based on whether you can ask for tickets with neither a noticeable accent nor any hint of politeness, annoyed the tourists, who saw that prices were up to ten times higher for them than the natives. How to avoid a tourist revolt? Thailand has the answer (via Siam Jai):
At San Kamphaneg Hot Springs, you can pay less than the posted English prices. All you have to do is figure out exactly how much less. How likely are tourists to have mastered Thai numbers?