Haven't read other posts, so forgive my possible redundancy.
I just put in every.single.extra.dime I have into flying. I look at things and say, how much is that worth in flight hours? Do I really need it? Am I really that hungry today? (sort of joking about that one). I spend all day at the airport so I can save gas going and coming (live kind of far away). Basically I eat, sleep, breathe and crap flying. Probably not an option for everyone.