A family with two cars (driving them >3000 miles a month seems a bit over the top but if so say so), that owns a home, takes vacations, is setting aside money for retirement while also saving for college tuition is doing pretty well imo - and yes, that's easily obtainable making $40k/year - hell they can even have cable TV, cell phones, and eat out of the house every now and then. This is the typical American... You can even sit at home smoking pot for 3 months of the year earning 30k and still afford this - ask Neo.
Yeah right. You aren't doing the math.
It's going to cost at least $200/mo in just license and registration fees, purchase costs, basic maintenance and replacing parts over time to have those two cars running. If they both get 20mpg, gas is $4/gallon, and one car drives 60 miles per day (30 mile commute) and the other drives 20 miles a day (errands, stay at home mom ferrying kids around), the cost of gas is $16/day. It'd probably be $500/mo in gas.
To take four people on a vacation is going to run you at least a couple thousand dollars, unless your idea of a "vacation" is wading through a swamp to dump some bodies for the mob. Say they're $5000 each, and the family takes two a year.
Now the costs for these things have already hit $8400/year for the cars and $10,000/year in vacations. They're going to lose at least 25% of their income to taxes, so they're left with $30,000/year. They now have $11,600/year left to spend.
Mortgages on a decent home near an area with decent jobs will run you $1000/mo. That's $12,000/year. Now they're out of money and just rang up $400 in credit card debt.
Now their two kids need college tuition saved within 15 years. Let's estimate the cost of college (including food, housing, transportation, books, and tuition) at $15,000/year currently, a degree being completed in 4 years. Let's estimate the growth of college costs at 10%/year. This means their college will cost 15,000 * 1.1^15 = $62,000 per year, and for all four years, that comes to $250,000 for one kid. For both it's $500,000. They would have to set aside $33,333/year to be prepared to pay their tuition given the above assumptions.
And they haven't even begun saving for retirement. It's generally accepted you need at least a couple hundred thousand to retire safely and comfortably. If they were to have $500,000 saved, they'd need to sock away $12,500/year for 40 years.
Well we're at about -$50,000/year. Try doubling that income to make this lifestyle affordable. This isn't even including the cost of groceries or cell phones or internet or cable or property taxes or home repairs or utility bills or health insurance or medical bills or any of that junk.