To me, it is not how much you make, but how much you save for rainny days/have in your pocket AFTER you paid all the bills. Take a look at the stories about McMann, Hollyfield, how those guys made millions but now are in bankruptcy/foreclosure.
If I have to pick 100K and work 70-80 hrs vs. 50K and 40 hrs <IF ALL things are equal>, then I will pick 50K anytime, been there, done that. No one ever say in their dead bed..."Geez, I wish I could work more hours and make more money".
It is also depend on location. 100K in southern states around here <LA, TX, AR> is pretty damm good but in Southern CA or NYC areas is just so so.