Actually this stereotype is about Chinese women. Thai women aren't that materialistic, and where it is true, it only applies to poor Thai women, who are attracted to the man because he's probably 1,000X richer than her, which would be attractive to a poor woman from anywhere. If a prince from Lichenstein came to rural USA, he'd have no trouble dating.
This thread is bizarre and confusing. There's only been like 5 posts and already people are conflating rural Chinese, Singaporeans, and Thais.
"Thai women aren't that materialistic" is incongruous with the West's image of Thailand as the home of pervasive prostitution, trafficked or otherwise.
It takes only a single documentary to disprove your claim that this is just a stereotype. There are so many about cringe westerners that buy thai wives.