Three things, mostly. How long the day is: an eight to ten hour tour costs more to run than a two hour activity. Whether a boat is involved: anything that crosses to Nusa Penida carries a return fast boat ticket, which is why those packages sit above a million rupiah while a mainland day tour does not. And how much is bundled: a Nusa Penida day includes entrance tickets and lunch, a chauffeured day tour does not.

That last point is where most quotes in Bali get slippery. A cheap headline price usually means entrance fees are yours to pay at each gate. Look at the included list on a tour page before you compare two numbers.

For the chauffeured day tours — Ubud, Tanah Lot and Uluwatu — entrance fees and meals are not included. You pay at the gate and choose where you eat, which usually works out cheaper than a bundled rate and always gives you the choice.

For the Nusa Penida packages, entrance tickets and lunch are included; personal spending is not. For the activities, anything not on the tour's included list is not included.