The falling dollar has no consequence in Dubai, so he cant use that, the Dirham is linked to the USD. Furthermore the fact that they are type rating you should have no influence on your pay, it is a tool required to do the job!!(a 3 year commitment may be required, but not financial.) If accommodation is included, nothing less than USD 60K excluding per diem would be acceptable, even for an entry level FO. If suitable accommodation is not included, don't go, cause it will cost you to much to stay there.