However: unless you are planning a very large family, this is a transitory phase. I noted as my kids matured the amount of crap you have to lug around drops precipitously. I can't see that many people needing to carry the stuff on the bulky end of this for years and years. I carried my kids sequentially in a back-pack (3 years separation, so #1 was walking everywhere when #2 came along) and managed to fit all the above (aside from movies) into the back pocket of the kid backpack (strongly recommended for the transition to walking, incidentally, as a backpack is almost zero hassle when empty, while a stroller is just as hard to push empty as full).

But back on topic: you could lease a car/van for the Peak Kid bit of your life and still save money.