to split the cost three-ways

[CanStopWillStop]

DH and I are going on holiday with a single friend. We're staying in a 2-bed apartment at £3000 and we're splitting it three ways, £1000 each. I told another friend and she was shocked and thought it should be split per room, so 1500 per room.

AIBU here? Is it not the most obvious split 3 ways? I would feel weird asking her to pay more just because she doesn't have a partner to split costs with.
For the record, i don't intend to try and change the split, just curious what others would have done in this 'throuple' situation?

Another for the 3-way split here.

You chose the rooms because you (presumably) want to stay in same room as your DH. You all share communal spaces, so adults should all pay the same.

This has made me think. With friends in this situation we’d split 3 ways. Unless there was a major difference in loveliness of rooms….

with family …I’m not sure…but probably by room…don’t know why.

and when staying with single friends in hotels….I haven’t really thought about the fact they are paying a single premium.

Yes it's an interesting one, I deliberately picked somewhere with 'equal' facilities, so two double rooms with ensuite. So many apartments had sofabeds or single rooms but from pictures of this one both rooms look equal, so I think the equal split makes sense too.