I did the shop for the first time in years on Saturday because the online delivery was cancelled due to the weather. I spent £100 which is more than we would usually spend for our family of 5.
It definitely is cheaper to shop online as the temptations to add unnecessary items is easier to scroll away from than it would be to run away from instore!
Needless to say Mrs Muzzy will not let me get the shopping in again (Fab News for me) due to the fact that the kids cannot drink beer instead of fruit juice
On a weeks food i'd say around £30, but every so often the odd thing pops up that i've missed or need for certain things. Amount of student vouchers/society cards we get given I eat out for about £4 a pop, but that's not too often. I could easily live on £20, but I try and keep my diet pretty decent.