A fair tax or discrimination?
National Parks in Thailand almost always charge foreigners (each park has its own method) more than Thais for an entrance fee, as do many tourist attractions including the grander temples in Bangkok, or places such as Chiang Mai zoo. The prices are often written in Thai numerical script for Thai visitors, and also English for those who can’t read Thai script. This has been criticized as being devious. A counter assumption would be hard to defend.