[Boudica]

Check the poverty line figure for your area, then assess your personal finances, when at least %33 of your income is disposable I'd choose that as my figure, so its dynamic. However the more the better.

33% sounds like a dream xD

You're absolutely right, though. A figure will be based heavily on location. It's entirely dependent on cost of living, and whether that includes paying for rent/mortgage/cars etc. Everyone has different needs.

For myself personally, I would *like* to be earning between £1500-£2000 per month, because I have high living costs. I could survive on less, but it would be survival and not "living". The ability to put a sum of money (min $100 or equivalent) into savings each month, would be my personal benchmark. Again, this depends heavily on location and lifestyle.