It’s often asked why non-Thais have to pay more than Thais for the same restaurant food, such as the buffet at Pattaya Park Tower’s revolving restaurant (Bt600 vs Bt400).
That difference comes from the common perception that non-Thais are wealthier than Thais. However, the 2016 gross national income/year of non-Thais varies from Burundi’s US$280 (Bt8,716) to Norway’s $82,390 (Bt2.56 million) (Source: World Bank), so to charge by GNI level is most impractical to apply fairly.
Charging tourists more than Thais commonly causes resentment that the foreigners are being taken for suckers, and this deters repeat visits. Also, foreign students have no income at the moment, but are tomorrow’s leaders – and Thailand would want them to think well of us.
Almost every other country I’ve been to charges the same for foreigners as for their nationals for the same services, and that fosters a feeling of fairness.
I’ve never been to another country where the official policy is to charge based on nationality – and see no reason why Thailand should be the first. Posting lower prices for Thais fools nobody, and if you’re ashamed to post them in English, you shouldn’t have them to begin with.