I actually read a really interesting article about this topic last year but can't seem to find it at the moment. If I can find it, I'll post it here.
It basically showed in some study or survey that was done that as a whole, the less people made, the less likely they were to look for the best deal on something or us coupons. The higher earnings a family had, the more likely they would spend time looking for the best deal possible or for coupons before purchasing something.
Besides groceries, I do not by (almost) anything without first seeing if I can find it for cheaper or find an alternative for less elsewhere.
I often wonder how my own brother affords his lifestyle.
He's pretty level headed and responsible but he brings in a good bit less than I do plus his wife doesn't work. I'm making roughly $10-15k a year more plus my wife works full time yet I feel like we (my wife and I) are always stressing about money even though we don't buy anything without first saving up for it and paying in cash/money we actually have in our account.
Maybe we feel like we're "stressing" money as our focus is zero debt and maximized investments and savings vs day to day living.
My brother has a second child on the way and just built a $1,000 computer.
My wife and I have 1 child and have not plans on having a second and I haven't paid for a computer outright in over 5 years. I took a bunch of free/hand-me-downs and sold them all to buy a new computer I wanted last year but no money out of my pocket.
Whatever he's doing is either working really well or they're racking up debt left and right, which I hope isn't the case.
EDIT: Saw some comments about cars and agree. My last "car" was 10 years old and had almost 200,000 miles on it before it finally got to the point that repairs far outweighed the worth of the car and were beyond my abilities to take on myself.
My wife's car is 11 years old and has 135,000 miles on it.
Our goal is always to hit at the very least 10 years of life out of a car before getting a new one and not having any car payment if at all possible.