'Decent' is a pretty relative term. What one man considers living well another may be appalled at.

You best bet is to look at how much you can make (or save) in your home country and then how much you can make (or save) in Qatar. There are hundreds of forums that cover cost of living for any topic, and lifestyle, you could want to know. Once you have those numbers you can decide for yourself on the minimum amount for what you would consider a decent life.

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Build a man a fire and he will be warm
for a day; set a man on fire and he
will be warm the rest of his life.
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