How much do you spend on food, household and family items per month?

So the way my SO and I handle our finances is we split the joint cost 50/50. We estimated that a total of $3000 dollars a month. This does not include our credit card payments, gas and car payments nor insurance. He is questioning me so I made a spread sheet of the last 4 months (that is how long he has worked full time at his profession). He is making me feel horrible. He keeps asking why is it so much, how much is this, how much is that. So the " store purchases " are where he has the questions.

I spend about 1k month on items purchased. Is that too high? We have a child in diapers.