@David *******
absolutely, as I said, buy a 50 baht Thai sim card in any
****
and top up minimum 10 baht each month to keep it alive. Can even top up several times in a row to "buy time" up to a year in advance. Yes that is the cheapest option to have a Thai number, if you don't need data plans etc, snd yes, it will work in an Australian phone unless that specific phone is locked to a carrier from Australia.