The combined salary of my parents is over 100 grand, but we get raped up the ass by taxes and struggle to pay some bills and stuff. We do have a bit of a higher standard of living than some other people though.
40k a year for a person living alone or with a spouse and 1 child could still be comfortable living as long as you know how to spend your money and chances are you'd be paying not too much in taxes with only a 40k salary. My dad has like a 37% income tax write now.
College for me would have been a real problem for us had I not received any sort of scholarship, getting to go for free is a big help.