Thanks for the answers. And yeah I've realized the pay is too low even though we dont live a luxury lifestyle ( my girlfriend has lived quite the local way of life earlier in vietnam for five years ).
It is a singapore company but with offices all over asia and 400 employees, and the benefits are actually better than those provided at similar offices here

So I think they are trustworthy.
I'm gonna try to get a better offer, if not accepted look for something else.
I think you should inform yourself even more, for instance think about that initially it will be quite expensive here, you will need to pay deposit for the apartment 1-2 monthly rents, you will need to get new furniture (if you dont rent furnished), cost of living here varies quite depending on your expectations if you live like a local eating hawker center food/cooking local food then its ok but if you want to eat healthy/western food it costs more than back home.
Also one thing to keep in mind is that its very different here with regard to apartment, if you want to move out from your apartment before the contract ends you will be liable to pay for the rest of the months as well - up front. In Sweded there is often a 1 month notice no strings attached, here its not so.
Also make sure you get healtcare insurance from the company, otherwise you will be paying out own pocket if you or your wife get ill. Another thing is pension, if you are not a PR you will need to put away money for you and your wife's pension, it is not automatic here if you are on an EP or some other temporary visa.