I just did an unscientific check of my credit card statement, and it looks like we've spent just over $1,000 in the past month on groceries for our family of 8. That's me, my wife, 6 year old, 4 year old, 2 year old triplets, and a breastfed baby. My wife is really good about finding deals at Costco, Aldi, and walmart, so I think that's probably a good number.