Location is important, we should be saying where we are. mid-sized city in Ontario, Canada here.
Lately I've been spending about $25-30 per week. It's a little lower than it should be because on Hallowe'en and Xmas I stock up on clearance chocolate to last me several months.
But I am a crazy bargain hunter. Almost everything I buy is at a great sale price. I buy in bulk when something goes on sale, and before I run out of that product, another sale happens so I am continuously stocked with it without ever being stuck paying full price. I choose which store to go to based on their flyer each week, sometimes going to more than one.
It's harder to manage with perishable foods though, being a single person. I usually get the large size and have to get it all in me like I'm on Fear Factor so it doesn't go to waste. I NEVER buy fresh meat because it's expensive and I don't have the energy to prepare/clean up. It just sits in my freezer until burned.
I also don't buy into the organic scam, so that's a lot of money not wasted.
I find the farmer's market to be a rip off except at the end of the day, when they're desperate to clear out stock and you can get fantastic deals then.
I'm a nibbler and dont' end up eating very much over the day (bigger guys will need to eat more to maintain). But the numbers I'm seeing amongst you other guys are astronomical to me. I could shop for you and save you a ton (with a little somethign for myself