Most street vendors will sell them. Best I've found is at the bintang supermarket
Thanks! Can you tell me what I should expect to pay? I use around 1-2gb a day.
Do be aware of the new registration requirements. If you buy your SIM at Bintang (which is not anywhere near where you are staying), you'll need to take your passport to get it registered. You can do this at the Telkomsel store near the Arjuna statue. so much easier to buy there, get it set up and registered all at once.
I was in Bali last week.
I don't know how long you will be staying but I saw internet packet(can be used all over indonesia) 10 Gb / 7 days 450,000 IDR(roughly = 4 USD)
be careful when you buy Combo or Special Deal Packages because they will be mostly video,chat,local data only data.
USD 4 would be more like 56,000 rupiah, not 450,000.
Just correcting it here in case someone reads it and gets confused with the current exchange rates.