I pay about 30K baht every year for insurance (AIA), it turns 3 years now. I had an operation on a gallbladder stone to remove it at the Phyathai Hospital in Siracha in 2nd year. It was costs 275,000 baht in total and covered by AIA insurance. Frankly, insurance costs some heavy on my shoulders but I'm satisfying and have no choice for living in Thailand 😅😅😅
Back to 5 yrs ago, when I applied for Non-O, I was so lucky. I visited Krungsri Bank in the government complex in Bangkok, I explained my situation such as opening a bank account for a non-O visa, and they accepted it without complications and I was able to open an account. It seems to be a case-by-case