In Reply to: first visit posted by Osocruel on Wednesday, 4. February 2015 at 03:44 Bali Time:
The VOA is US$35 per passport, so it's regardless of age.
There is also a departure tax you pay at the airport after checking in for the trip home. It's Rp200,000 per ticket holder - so you wouldn't have to pay that for the youngest one.
I hope you enjoy your trip :)