is the job/role itself. Its easy to get caught up in figuring out the economics of the move itself at this stage.However one thing you seriously need to consider is the role itself and the organization you'll be joining.Is the role challenging enough.Whats the work culture like at the 3 places you mentioned ? Take claim's about a culture based on openness,meritocracy etc etc with a very large grain of salt.I don't care what anyone else says,be prepared to get rusty professionally after having spent time here.Its ironic but the pace of things here can be so slow and the lack of exposure to a challenging environment means that you are bound to be at a disadvantage if/when you go back home.
On thing you mentioned is that the position offered is on a "permanent" basis and not a contract . What did you mean by that ?Depending on the company,everyone here starts with a 2 or 3 years "contract" .

Also your post on 01/11 said "not married yet". Post on 01/12 says "my wife". Which one is it bud? As someone pointed out,you have to be married if you want the company to sponsor your lady.