There are a lot of insurance company in Thailand and each compant has different prices for different packages you will choose, but rough it will cost like 100 dollars monthly for health insurance here in Thailand.
"Baan Smile is a wonderful service for anyone who wants assistance navigating the Thai immigration system. They offer a wide variety of services to help expats who move to Thailand. They helped us with visas and finding an apartment. The staff responded to e-mails and texts quickly and were always very friendly. I highly recommend Baan Smile."