Indonesian 7-day visa on arrival was $10 still in April. Departure tax for international is IDR100,000 (I guess it was a typo, since the dollar amount is about $11 indeed).

I don't know about CGK, but in DPS they always collect the passanger fee, even if in transit (they have a special counter for that in transit area); but no need to go through immigration or pay visa fees.

CGK is the same. Unless you pay the departure tax you won't be getting on the plane.

I will be doing this turnaround at the end of August. Any recent experiences? Christep - did you do it in the end, and how did it go? Thanks.

Yes I did a CGK turnround (in F). It's been a while so I can't be sure what happened with the tax, but I recall that CX met me and helped the process along, and everything went smoothly. But then the plane went tech after we had reboarded and I had an unscheduled night at the Sheraton Bandara courtesy of CX, but with no overnight stuff since I was expecting to be home that night (lesson learned there).

Edit to say that on reflection I recall that a CX lady met me off the flight, escorted me through a sort of security point to the departure lounge, took some money off me (probably US$10) and returned with a receipt. The transit went very smoothly indeed. It was just the going tech that was a pain - fortunately I was doing the run on a Saturday not a Sunday, otherwise I'd have had a tricky job explaining to the boss why exactly I was flying back from Jakarta when I should have been in the office.