@A-b,
What I heard from one friend is...300-350 $ per day (co-pilots), and 400-500 $ / day for captain position (depends on experience). Instrutors and TRE are on higher rates....Only rumour info.
If you work 6/6, it s 180 days in a year (180x350$ = 63 000$ ), because you are not paid when you are at your home. And yes, if you work 360 days/ year it is 126k $, but ...
For GHC you need type rating AW139, S-92 or ( at least ) B-412...but they are going to finish with 412 in next few years ...
Only rumour info...Too.
JR