Doesn't Airbnb add their commission to any additional fees? They don't add commission to tourist tax, but my understanding is that anything else is commissionable.
In winter, we have an additional e ergy charge to cover heating and increased elecricity consumption. Guests sometimes ask why that's not included in the (already heavy discounted winter) price. Well, the price would increase not only the amount of the energy fee, but another 15% on top.
So, we have to collect it on arrival.