flinders wroteI return to Australia each 12 months and buy the Travel Insurance there to last 12 months whilst I'm in Bali. It will cost about A$1,000 for budget cover which includes evacuation.
I think they'll probably pick up that you're repeatedly getting a new policy every 12 months, and if you ever made a claim, I'm pretty sure they'd enquire about what visa you're using while staying in Indonesia.
Because of your age, there's just no cheap and easy option. Sucks to be old, I guess.
You could revert to using a Sosial Budaya visa, and add a 6 month visa run to your yearly schedule. Just a thought.