2 adults, 2 teenagers (18 & 13) and 2 children (9 & 11) I spend £500 a month at Waitrose. (That includes toilet paper, kitchen roll, Dreft washing powder etc)
I cook from scratch a lot and take advantage of the 2 for £8 meat deal quite a lot too.
We eat very well, things like jambalaya, jerk chicken with rice and peas (peas are kidney beans), risotto, fish every Friday (Plaice, lemon sole, cod etc) steak a couple of times a month, beef casserole, pie & mash, roast dinner every Sunday, a full English once a month etc.
I also have £100 a month on top of that in my budget for the treats shopping. We don't always necessarily need to use that whole £100 but it's for things we don't eat all the time; sweets, stuff for movie nights - popcorn, ice cream, big share bags of crisps, snacks or we might use it for a takeaway etc.
Stuff like toothpaste, toothbrushes, deodorant, misc sundries etc I buy as and when from either Savers or Wilko if they're not on offer at Waitrose.