How secure is his current job? If he's a new hire, he may be among the first to be let go if his current employer downsizes.
How much tax will he have to pay if he's working outside the US? US expats are still liable for US taxes, but (iirc) the level of taxation depends on your home state.
What other additional costs will you incur? Flights home? School fees? Medical?
How secure do you think the job in Qatar is? If they're offering close to US$100k plus benefits, they should be willing to pay relocation, and maybe fly your husband out so that he can get a feel for the place. If they're not willing to invest up front, be skeptical.
A few questions to consider:
HTH.