Narcissism is a complex psychological disorder, with many facets. Such as the need for praise and attention, lack of empathy, a grandiose sense of self, entitlement, envy of others.
I have none of those attributes. Calling me a narcissist, because my current relationship of more than ten years started off as transactional, is as shallow as a mud puddle.
BTW, my previous two relationships were 28 and 16 years. Narcissists shed relationships like deciduous trees.
Give me an estimate, if you know so much about it. What percentage of relationships between Thais and foreigners start out as the loving, caring type you describe, and how many started as transactional?