Polygamy in Thailand could be freely practiced before 1 October 1935. Polygamy was recognised under civil law. The old family law assigned wives to three categories, in accordance with the way they became wives.

How much is a wife in Thailand?

Usually, in Thailand, the bride price is between 50,000-300,000 Thai baht, which is equivalent to around 1,600-9,600 USD. Note that since you are a foreigner, the girls family may demand a higher price from you.