Daycare/nanny is expensive from what I hear.
Not nearly so expensive as going to medical school then not working as a doctor.
Do you guys think putting the baby in day care for one day is cost-effective?
Depends on the center; some are quite flexible. At our daycare center, there's a minimum number of hours required for each room. It's 30 hours/week in the younger rooms; 20 once they hit three or so. You are allowed to design your schedule however you wish. I suspect for a single day of care, you might be better off with a part-time nanny or a nanny share?