I've been trying to think this way, too, and convince my husband of it. He has Crohn's, and so is on a special diet. So, either we make everything from scratch, or we resort to paying the crazy amount for things that are easy and fit in his diet. For a while, he was picking up LOTS of days of overtime, to pay medical bills, etc. But, since he was working all that overtime, he was eating a lot more expensive convenience foods because there wasn't time to cook every meal. And, I was stressed to the max with two kids, and never any relief because he was always working, so breakfasts and lunches were almost always convenience foods for me and the kids.
Then I looked at our Discover
cards "Spend Analyzer." (We buy everything with the credit card and pay it off in full every month, and get $10-30/month in cash back for doing so). Anyway, the spend analyzer shows you how much you spend on Groceries, Gas, etc in a spiffy little pie chart, with numbers. And, the months that my husband was working all that overtime, we were spending 1,300+ per month on groceries for the four of us! On the months that he wasn't working as much, we were spending more like $800. Part of that number is that, when we're stressed, we stress-buy more canned/dehydrated/shelf-stable food. So our house is full to the brim of non-perishable food stuffs, which really isn't the worst thing. But, the rest of the money is going to convenience foods.
Every month, then, that my husband works 4 days extra, we end up spending about $400 extra on convenience foods. That's two days worth of his pay. He worked two days just to buy convenience foods! And so I said, "Would you rather be spending those two days here at home, playing with the kids, cooking food, working around the property...or drawing blood at the hospital and having us all more stressed?" This last month, he didn't pick up any extra shifts, and I've been able to cook more, my son is less stressed, we got a TON more done on the property, and my husband is able to spend more time on his fish, and everyone is more happy.
I think it's really good to have a deep look not only on the time we spend on work-related stuff, and how much work you have to do to buy something, but also all the little expenditures that occur when we're stressed or have less time. How do we want to spend those hours--because there's only so many of them in a given day!