When I moved to Switzerland almost ten years ago, I got pretty much an 80% pay increase.
That increase came from daily allowances, travelling and living expenses.
I also got my accommodation, travel and "other" expenses paid.
That all changed when I left and moved to Switzerland permanently and had to "fend" for myself.
Now, I'd say I'm only slightly better off - in a financial sense, but to be honest, I'm not sure it's worth the trouble.
You're looking at a ~ 50% - 60% increase.
Make your decision based on what's right for you and your family.
Consider that if you go it alone, you have many things to consider
- travel
- registration
- work permit
- accommodation
- language / culture - especially important if you have family with you
- health / medical costs / insurance
- tax affairs
With respect, $800 is not a great salary for an AIX admin. Unless you're very adventurous, I'd stay put.