Salaries
Surely if we are going to compare salaries across the board they should be after tax, if you pay any. Post tax salaries would then only have to take local cost of living into account.
I think Dr Evil's quote of 80,000USD is a little mis-leading. It includes accommodation allowance, all of which goes towards either paying rent or a mortgage, and so you wouldn't see any of it in your pay packet as such.
I believe more realistically it's more like 51,000USD (ish) as a base salary plus your allowances. Top salaries for supervisors would be somewhere in the order of 65-70,000USD.
Those allowances like accommodation, schooling, health insurance etc are just essential for living in this part of the world. Most schooling would be free in home countries so if you don't have property back home your saving on not having to pay for accommodation costs.
The nature of how the salary and allowances are packaged differs from unit to unit.