Among the pax are the cooks, the stewards, the first time roustabouts: they're all getting better money than the drivers who have invested money, time and then years of experience to get where they are.
That's my point - it's a fallacy to say that.
I work for an oil company at the same salary grade as an OIM, so I have some idea of what the figures are. My (UK based) base salary is somewhere at the bottom of the current UK North Sea Captains' scales (like year 2-3.) It's true that there would be additional allowances on top of that for an offshore employee, as there are for offshore based helicopter pilots.
I'm not aiming to start a bun fight about global salaries - far from it - I'm just trying to point out that to perpetuate the myth that everyone on a helicopter earns more than the pilots does nobody any favours. If used in the negotiating argument it may even be counterproductive as it will be shown to be just that - a myth!