Daycare at a licensed place in Chicagoland is probably $1200-1500+ for an infant, and goes down about $100/yr (Edit: month) as the child ages. You can go in-home of course, but you then run the risk of many other things, including being at the mercy of an individual (who sometimes gets sick, takes vacation, etc) versus a company where they will always have adequate coverage. I've also seen a lot of personality type disputes with individuals (my SIL has a nanny who gives a lot of pushback on changes to schedule, etc) versus everything I do with a company is a "business transaction" and there's less emotion. Many of the people I know who use in-home daycare are teachers, as in-home seems to be more in line with the shorter, more structured workday and regularly scheduled breaks. We need the flexibility of a place that's open more hours (daughter's current school is 730AM to 6PM for aftercare) not because we use all of the hours, but because sometimes we have early meetings and drop her off right at opening and sometimes we need to stay late and pick her up right at close, and often those demands are sudden (find out at 4PM about an 8AM meeting the next day) and that doesn't work as well when dealing with a single individual.
So yeah, I dunno about the 10 years, but $2500/mo for 2 kids is not a shocking number by any means. And, as discussed in another thread, even if it is borderline on whether or not one parent still works, you must take into account the ease of entering the workforce after an extended absence, and the loss of compounding raises, etc. My mother stayed home with us kids, and while I know she doesn't regret it, she never was able to get a job in her chosen field again when she wanted to return to the workforce, and it took a long time (over a year) before she could get a (professional) job at all. It's not at all as simple as saying "I pay $2500/mo, I only make $3000/mo, this is silly", the effect of not working can last much much longer.