This whole thing is a brown envelope pig slop fest between the government and the Thai General Insurance Association. At my age, the 400,000 coverage amounts to about $13,100 US at 30.5 to the dollar. For this I would pay a 59,000 baht premium (one of the least expensive I found). That's almost $2000 a year.
I busted my ass and made my fortune and self insure. I can afford it. This is nothing more than another fee to live in the kingdom. The coverage is absurdly inadequate and the premiums usurious.
It really beggars belief.