Thailand is "Land Of Scams" - LOS
Thailand will never be able to stop with dual pricing, unless they make not only illegal and a crime by law, and set a high fine with prison.
Since, it's easy to understand that dual pricing is both racism and discrimination.
And as long as even some Thai tries to charge 80 baht instead of 40 baht for a meal of food, it will always be a Land Of Scammers.