Jo

Will not repeat what everyone is saying, I've just recently been negotiating my own contract in Dubai.
The company will probably try to push back arguing you'll have a big variable/bonus and that will make up for a lower basic & allowances.
All I can say is that the best time to negotiate your pay is before you start! once you're there the opportunity is gone.

If they do not want to increase your basic definitely go for increasing your housing allowance/number of flights home/etc but is better to push harder at the beginning.

From what I've seen on this site as well as others, and costs of living etc salary is looking low. My rule is always, without bonus would I still be comfortable and better off.

Good luck!