I wanted to ring Australia a few times when we were in Bali last month.
I knew it was going to cost a few $s. Thats fine enough as I knew what to expect.
For your info and possible benefit:
I have a Telstra mobile, on a plan with International roaming.
The calls cost approximately au$6.25 per minute
If you receive a call while you are in Bali on your Aus sim card with Telstra, you pay approx au$1.30 per minute.
To sms from Bali to Aus, usually 35c each
Mms about 50c.
I always buy an Indo sim card and use it to sms or call locally.
As they say, let the buyer beware.