it doesn't matter if he is unhappy at work, or even if he makes more money.
what does he value? lunch or that 5k more into savings?
one thing you have to be careful about, and i see often on this board, is that assumption that the money saving spouse is on the side of right.
if he doesn't want to retire early, or save money then it doesn't matter. but re-read and it sounds like he does, but he also values lunch out. is lunch out interfering with his other values, if so point it out, if not let it go.
at the end of the say i like to thing : which hill am I willing to die on.
Am I willing to argue over 5k in lunches if I am on a pretty good path to retirement already? which it sounds like you may be.
to be honest, it sounds like he is pulling his weight equally so he should have equal say.