I lived a while ago over the bay in lovely Doha, did fly for their lovely airline over there(if you find sarkasm, you may keep it ;-) ).
I was a captain on one of their widebody fleets, same pattern, barely never at "home" in Doha(which is in fact a bonus if you are single, but not good for a family father and husband).
I think costs of living in Doha (at that time) have been lower then in DXB, even there are less things to do(and spend your money on).
BUT - even on a captains salary, there was not really that much money remaining - if you lock your family in the house maybe yes, otherwise, not really.
Life in the ME is expensive, if you buy books or DVD's in the Virgin store, some dress or other non arab made stuff, all is expensive. Often twice as what you would pay in shops in Europe.
Then there are the extra costs for school(uniform, sometimes books, registering fee, etc.) which are not paid by the company. Normally they just pay for the annual school fee(seems to be the same in EK).
Normally you need a club membership for your family, gyms at the company facilities are lousy, pools hot and barely cleaned, which makes again up to 5000 USD/year/family. Depending how "fancy" it has to be. But you want something with a big inddor pool or a cooled outdoor pool(otherwise you swim in a 40°C soup over the lovely summer), and that is usually not cheap.
THEN you want to bring them most likely out for eating every now and then, and there you can really spend a sh**load of money on(I was surprised how much one of this nice restaurants in front of this bloddy "music" fountain is costing. Shocking.(Have been there on one of my last rotations with my current, european, operator. Doing a layover. And one of the FA's told us that we HAVE to see that place.... Well, I have seen enough[and paid enough]).
Sure, then there are lots of cheaper place where a pilot would went to. At least that's what I did after that "fountain incident". But if you are anyway barely never there and then go out with your wife it should be something nice...
And we could go on - if you are not there because they always keep you flying your family would most likely to have a life and not sitting locked up at home. And everything comes with a big pricetag down there.
If you have still a life(e.g. flat, house,insurance...) back in your homecountry it will cost you as well a bit. For a European(Western) usually this means a good amount of money spent there. I had all of above and at the end there is not much remaining of a captains salary, I can imagine (or better, I can't) how to make a decent living on a FO's salary(talking of a man with family and kid(s) not a kid enjoying the ME of course).
I must say I do not (and never will) regret saying goodby to that shiny(and fake) ME world.
I earn now much much less but have a life, have time with my family. Much more then I ever had down there. Plus I know I always have legal means against my employer in case ever something is going seriously wrong.
Below the line there is nearly as much money remaing as it did on my much better paid job down there. As a bonus I live where I want and see a nice landscape if I look out of the window.
Especially for UAE/Dubai consider as well - they will implement the VAT very soon(I think I read somewhere 10%) plus earlier or later there will be as well income tax. And it is not sure if they(EK) will really increase the salary. After all they need to earn the money first before they can spend it. Dubai is more or less broke, so not much money can be pumped into the airline, not like the much richer brothers in the neighbourhood.
If you have been a Captain before plan to sit on the right seat for a while, I think 5 years will be a realistic minimum. But it could be much longer as well.
As a South American you have one bonus - the earned money in the UAE is much more worth back home then in comparison for someone from Western Europe. Or Africa(I flew with some guys back then and with this money they earned in QR they have been like small kings back in their african home country - farm, tons of workers, etc.). I instead repaid the loan for my small flat back home, and that was it.
Consider well what you want to do and how long. Make yourself aware that commiting to one of this airlines is a long term commitment. Especially as a FO. Otherwise it will just cost you money and a lot of stress.
If you never have been to the ME before consider having a trip over there and think if you really could stand that sand, dust, traffic, unfriendly people, heat, high prices, poor building quality,... for a lot of years, not just for a week of holidays(whoever would go there for holidays, but that's a personal choice).