I never heard that Costco has good quality stuff but if you buy in bulk they said it comes to cheap compare to other stores. when I did shop there I was looking at the stuff I normally would buy. But to be honest, I didn't see much difference. One of the stuff I looked at was bread and they were selling 4 bread in 1 package and when I divide the amount they were charging it to 4 I found that there is only 15 or 20cent difference. In my family we are only 2 plus day care kids so I woulndt know how much diapers, wipes would cost. For us it wasn't a big saving and we didnt wanted to buy in bulk. We would rather eat fresh. Plus we didnt wanted to pay for a membership fee.