Maybe i can give an alternative perspective... 34 with 2 kids, crappy undergrad but worked my way up and always managed to have a sustained work-life balance. I've NEVER done an 80 hour week, probably the most i've ever done is a 60 hour week. Family balance is also imperative to me and finding that balance along with career choice is the key. Blasting away debt quickly is not necessary the way to go. To give a quick summary of my career.
1995-97 - Graduated - took easy jobs so that I could focus on music career ($12k pa - 37.5 hours per week)
1997 - relocated to London, took jobs to pay rent ($26k - 37.5 hours per week)) - switched departments due to high performance
1998 - changed company for pay rise ($42k - 45 hours per week (2 hours per day commute) = 55 hours per week)
1999 - changed company due to commute ( $50k - 37.5 hours per week)
2000 - $68k (37.5 hours)
2001 - $72k (37.5 hours) - bought house for $380k
2002 - $75k (37.5 hours) - got married
2003 - relocated to Tokyo as independent consultant $120k (with approx 3 months vacations during that year) - 37.5 hours per week.. I billed by the day, and i specifically put 7.5 hours per day in the contract.
Kids born 2005 and 2008
Not stellar money, however money was never my goal and as you can probably see from the working hours, a good balance is what I've always targeted. However, one advantage i did have, due to the musical aspirations, whenever I went out, it was usually to DJ and I would get lots of free beers and a bit of cash.
In terms of recommendation, all I can say is that moving abroad was important mostly because the wife was on an ex-patriot package as an international teacher which helped to subsidise overhead costs such as rent. Plus the hours we worked meant we could spend a lot of time together and give lots of time for the kids. As such I have a huge compilation of videos of my childrens upbringing, our interactions and treasured moments of fun, something which we can share together. That's something a succesful career cannot buy. So for me the MBA is all about giving me options in targetting a path i want to tread.
Things like eating at expensive restaurants are not a concern for me, i prefer to cook, and to be honest, I can cook just as well as a lot of good restaurants, if not better (parents have a background in catering).. plus I enjoy it, and its certainly cheaper than constantly eating at fine dining places. (e.g. people pay through the nose for Fois Gras, but its half the price to buy it and cook it yourself... and it's not difficult and you can make it suit your tastes moreso than a restaurant) furthemore, learning to cook good quality meals can be fun to do with the family and trains a great skill.
The other thing to look at, if quality of life is an issue, is relocating to another country where you could increase QOL on a lower salary. It's one of the main reasons a lot teachers go into international school teaching... fully paid apartments with maids and drivers, private healthcare and plush apartments... basic salary may not be great, but expenses are extremely low and lifestyle is extremely high. Have you considered moving abroad to do your MBA? I took my family with me to Hong Kong to do mine (wife not working).. one advantage of this, is she is now integrating into the ex-pat community and helping me to find networks which are not accessible through regular B-school networks.