If a landowner is in the business of providing helicopter landing services (by charging a fee, for example), then they have a higher duty of care towards you (than they may realise). The article
here suggests that, in a negligence case, the "Duty required" element would probably be satisfied if landing fees are charged. It doesn't address your gripe, though, which is more to do with the high level of fees or the fact that they aren't subsidised by the room charges. I suspect they have found that some charter customers have been happy to pay the fee, especially if it is not itemised in the overall cost.