Compared with the local average living standard and consumption, 500,000 baht can lead a relatively affluent life in Thailand. Prices in Thailand are relatively low, especially compared with first-tier cities in China. For example, the property prices in Thailand are relatively low except in downtown Bangkok and some blocks near the subway.
However, compared with the local upper class or wealthy class, 500,000 baht may be just an ordinary income level. In some high-end areas of Thailand, such as luxury apartments or country resorts in Bangkok, 500,000 baht may not be able to maintain long-term living expenses.
In addition, the social environment and culture in Thailand will also affect the cost of living. For example, if we pay attention to education, medical care and social expenditure, the cost of living may be higher than the average.
To sum up, whether 500,000 baht is rich in Thailand is a relative concept. If compared with the local average living standard and consumption, it can be considered as a relatively affluent living standard. But if compared with the local high-end life or specific cultural environment, it may be just an ordinary living standard.