nairobi (Keneya) or Invercargil (New Zealand)

i was planning to move to invercargil (New Zealand) from past 8 months and have given so much into it itterms of money as well as time. my wife applied for student visa and i got dependent visa with full time work permit for 2.5 yrs (1.5+1Yrs). My wife's passport is already stamped and mine is expected in week's time or so. we were all set to move for kiwi land and i have already started applying online for jobs there. in the mean time i attended a interview for Narobi based steel company and got selected, they offered me USD1500 p.m (tax free savings) and USD 700-800 p.m for local expanse plus married accommodation, medical, fare, holiday etc as per general African expat contracts. now i am confused which one i should select?? i am getting job and a good job that too in my field, steel!! on the other hand if i look at longevity i find NZ a better option m confused, have already paid the fee in NZ (Refundable wid lil deduction) if anybody can suggest what to go for????????

pleaseeeeeeeeeeee............