Ok, yeah, I feel like we're spending a ton now, too. We're a family of three (one meateater, one vegetarian, and one infant who is still breastfeeding...oh, and a 100-lb dog). We spend about £65 every 10 days on groceries, and we also do a big Costco shop once per month.
I will only buy nappies at Costco now. Pampers are the only thing that work for the baby, and they are ridiculously cheaper there. I got 145 nappies for £13, whereas you can only get about 78 nappies for £11 at Tesco or Asda, it seems. DH buys mince and chicken breasts in bulk at Costco and separates them into freezer bags. But that is about all we can fit in our freezer...it's tiny tiny. I wish I could buy more in bulk and freeze. If we owned out house, I'd get a separate freezer for the garage, but no point right now.
We usually buy other groceries at Ocado. They seem to send me 15% off coupons by email if I neglect to shop there for more than 10 days, so I wait for one of those. I found shopping at Ocado really helpful, because I meal plan and just get what I need. When I go to Tesco or Sainsbury's, I throw all kinds of crap in the basket (biscuits, ice cream, pre-cut fruit, crisps, etc.) and it adds up. Ocado also is very close in price to Tesco.
We never or rarely eat out, so we buy a lot of stuff. I also eat a lot of fresh veggies and fruit, and we both drink a lot of Coke Zero, which is expensive (Costco is good for soda, as well). I also don't like buying the cheapest stuff, as it seems to be worse in quality. I will pay a little more for good veggies and fruit, cheese, bread, and the like.
I should probably review what we're spending, because it seems like a lot. But I know we've gotten much better since mealplanning and using Ocado.