I moved to Thailand 30 years ago.Dual pricing has not been an issue where I live outside Phan in Chiang Rai Province. Except when travelling to main tourist places like Phuket, Koh Samui, national parks and other similar places. Phuket is the worst of them all, Even with my Thai ID card I have to pay tourist price at the parks. This was not an issue 20 years ago. I don't visit parks anymore, because beautiful nature that I experience when I visit Sweden and Norway every year for free is after all superior to Thai parks. It is different here, but not very special. I also experience the same nature free, at many places in the local community. When I go to a tourist trap I stay clear and invisible and let my wife do the bargaining when we want to purchase something.. I only show up when it is time to pay. I am really pleased how honest sellers are locally, even in Chiang Rai compared to other tourist destinations. But at tourist trap destinations I am just a shadow behind my wife to avoid being scammed.