As for your hypothesis, I can support it with at least one anecdotal data point. During my lean academic years I actually kept track of all my expenses in a little book. Some months I made a point of eating out, and other months I ate mostly at home. The difference never amounted to more than 10% of my total food expenditures either way. Feel free to use my results to justify your habits. But please, whatever you do, don’t repeat the experiment, because I’d hate to find out I’ve been wrong all this time.

My roommate does all our shopping (and brings home everything from pasta ingredients to frozen dinners), but when she’s gone I tend to shop at Costco (with forays to TJ’s or Safeway for perishables like salad makings). I can buy the supplies for a month of glop (the casserole I lived on in grad school) there for under $30, I think. Potatoes, onions, meat, cheese, BBQ sauce. I add herbs/veggies grown at home, plus anything I have around the house that might go well with that. I like to eat in peace and quiet as frequently as possible, which means eating out is … bleah. Noisy. Pricey.

Give me a bowl of glop and my TiVo or a book and I am a happy diner.

While this technique might work well for you and your unabomber cooking skills, I calculate that eating out every night at a decent restaurant would easily cost us about $250 a week. We probably spend that much on a months supply of groceries. Works well in theory, but my bank account would cry foul.

Though I will agree, grocery shopping is a waste of time. It would be a better experience if grocery store owners designed their stores with customers ease of use in mind instead of their profits. Having to venture to every corner of the store or walk through a maze just to buy a few items drives me nuts.

Oh and one thing I’ve noticed in the cereal aisles of some stores, the sugar filled kids cereals are always on the bottom shelves, strategically placed at a little tykes eye level where the bran and fiber enriched healthy cereals are on the upper shelves. Nice.