I have been through all this for a deceased swiss friend. His family live outside thailand so gave me power of attorney to act on their behalf. It took about 14 months much of which were delays in Switzerland proving his Will.
After I appeared in Court here, it was about 2 weeks later, that I received papers from the Court, acceptable to Bkk Bank to release the 800k..
With a properly executed thai Will, the process would have been much faster.
For general interest, he had executed a Living Will here, to avoid unnecessarily extending life on tubes and machines, if it was clear that recovery was impossible. When his time came, that helped.
I also have a Living Will, and, like him, carry a body donor card, from Maharaj to support training of new doctors.
(I am merely sharing info for those interested and will not get into any debate about the rights and wrongs. Personal decisions)
infinitely variable depending on age and cover. And exclusions, co pay etc. Be aware they either stop cover as we age or jackup premia to price us out. A self insurance fund is better imo. As a very rough ballpark, my emergency burst appendix cost 160k bht - which I thought was cheap.