Thai Families are very tight. IF the family is DEMANDING a dowry.. run away. But in all honesty, I would not have an issue with paying 120K to 250K dowry.
You must always know that the daughter is responsible for the parents. Her job is to make sure that her parents are setup into the future for retirement.
If you do not understand this, do not marry an Asian lady. Plain and simple. Do you not want the same for your parents? The gold is just like cash. Thais can sell gold in 30 minutes. Do what makes you happy.