JPPR2, you've offered one of the few responses I can see here with truly valuable advice.
Meanwhile, having a bit of protection in case you get clipped by a scooter isn't a bad idea.
You do NOT have to deal with those international crooks like BUPA, ALLIANZ, etc. You can get a decent, minimal package HERE for as little as a couple hundred buck A YEAR.
https://www.thaihealth.co.th/2012/product_simply_eng.php