First you suggest someone bringing home 1400 a month can save 400 of that.
Then ya suddenly figured out people have other obvious basic living expenses like food, utilities, health insurance, medical expenses, repairs, clothing, taxes on everything ya buy and on and on, and they you suggested it might be only 50 bucks a month he could save.
Saving 400 per month suddenly goes to 50?
Which is it?
Someone saving 400 per month from 1400 take home would have to be 16 years old, living at mom and dads, where he didn't have pay for anything but fun stuff.
Get real...You clearly do not live in the real world.