I did some research on Google regarding this topic and most of the results are quite negative as people doesn't like this practices from some countries in the world. Conclusion from all the results is that this happens only to 10% of the countries in the world and only in one country it seems perfectly legal. Also they are all severe poor countries, or nicely said - developing countries. Almost all of them are in Asia.
I read more then hundreds questions and answers from people online on dual pricing that inspired me to write on this topic something that i think others deserve to know. As I am living in the leader country in the world for dual pricing according to Google results i have quite an experience, even conflicts with the people and owners here in Thailand.
Lets be honest, if every country in the world have crime then in every country you can find dual pricing, thats why there is a big difference between legal and illegal dual pricing. At my knowledge, please correct me if im mistaken, i think the only country where dual pricing is legal and strongly forced by the government is Thailand. So this creates another problem and thats racism for the pure reason that legal dual pricing started to be implemented in the shops, not only national park and museums, but in normal shops like barber shop, or printing shop, or even restaurants and street food venues. This is the point when the tourists felt cheated, and not at museums and national parks, there is tolerance there as the country is helping their own people same like giving them social security money to unemployed people, witch every country does. So on the government property in normal noncitizen to have different treatment then the citizen. But imagine if every single shop in the country you just visit is treating you as someone that by the law will have to pay even 10 or 20 times higher price then locals. How would you feel? Like all the world is against you? Like you are some kind of freak, not equal, alien or African person in the slavery period more then 100 years ago?
I went in Bali this year 2020, before the pandemic and i visited more then 10 national parks, you know how many of them have dual pricing - 0, yes zero. They even allowed me to use the same ticket for the next day cause the day when i bought the ticket it started heavy rain and i didn't had the chance to see the waterfall. If you like to compare countries on this topic just search on Google "DUAL PRICING" and you will see for which country is the most applied or practiced.
In Bali also had a negative experience on this topic, as i saw street food that many teenage kids where buying in front of me in group so i decided to buy and as i was standing in line i saw all of them are paying 20k indo rupees so i figured out and i didn't asked for the price i just said one please same like him (the guy before me) so i just paid 20k but the seller said no no its 100k and i said no, he paid 20, and i said i like same dish like him, but he still didn't accept and started to talk Indonesian. So i asked the kids how much, they speak good English and they explained is 20k and they talked with the seller and then he accepted 20k. So what is the point here? If the country make dual pricing illegal, then the sellers and shops and restaurants will be ashamed to ask higher prices just because you look different from the locals, but in Thailand, as from my knowledge the only country in the world that dual pricing is legal, different prices are displayed publicly in front of the shops and venues and foreigners are paying 10 or 20 times higher price even for barber shops or restaurants or street food or shopping malls venues, its like 90% of everything you do in Thailand you will pay like 10 times more then others and nobody is ashamed to do this or display it publicly as its seems totally legal.
This is happening many years even decades and tourists didn't cared too much because it still cheaper from their countries, but now the rising of the thai currency and drops of other currencies is playing crucial part as well as the world pandemic 2020, so people are starting to address this problem, as they created website 2pricethailand.com that generates information about the dual prices places with the picture proof posted on the facebook group facebook.com/groups/2pricethailand. This is making foreigners aware what locations to avoid if they dont like to pay 10 times more.
I was blackmailed and threatened from owner associates on facebook because i posted in the facebook group about his place just a picture as a proof of dual pricing. I was forced to delete the post as they wanted to hide the fact that the place was charging different prices for foreigners even if they have work permit or driving license in Thailand as proof of long stay or residence. That associates also posted on his own profile a question if its okay to have dual prices for his place, and over 300 comments (his friends on fb) agreed with him. This is what worries me. When people want doesn't separate the the common sense of logic and fairness from their own material interests. Those people have no quilt cause for them unfair business is just a way of living and there is no law that can stop that.
The most of the reasons that locals in Thailand provide on the topic why dual price exists is - the taxes. Who pay the taxes they will have the local price, and who doesn't pay taxes he doesn't deserve local prices and he should pay 10 times of the local prices. But they are missing something and that is - visas. Foreigners are paying very expensive long stay visas with very hard conditions like almost million baht deposit in thai bank which is 35000 euros. Visa agencies are asking couple of thousands euros to help issue to visa plus a lot of additional payments as they dont mention before the first payment. Also tourists visas are almost same amount as they stamp you on the border only one month even if you have 6 months visa issued in your country from thai embassy and forcing you to do "visa run" what is practically crossing the border and entering again every month and you are allowed only two times per year. All that is very expensive to do and they dont care if you are from poor country, for their logic all the foreigners are Americans and have lots of money.
Dual pricing is not only unfair practice that is considered scam everywhere in the world except in Thailand, but also is dangerous for the long term sustainability as scammed people are not returning back. At this point as Thai economy and GDP depending on foreigners more then 50%, the danger is very much visible and felt in Thailand as more then 50% of the all businesses are targeting foreigners and tourists, and all of them are now closed and probably will remain closed or partially opened for years to come. Its time for people to understand that cheating is not a way of living.