@Cedar: Interesting about the extra $40 per shopping trip. I have to say that my typical shopping is done at least once/week. That is the best way to be sure to catch all the sales on the grocery store's specials. Many items go on sale about every 6 weeks or so in a rotating cycle, so if I buy enough to last at least 6 weeks of a great sale item, chances are good that I'll catch it when it goes on sale the next time -- but not if I only shop once/month.
I think the problem can be solved with discipline (and never shop when you are hungry 
) I typically check out with only the sale items in my cart and nothing else. Of course, I am grateful to all those impulse shoppers who make it possible for me to get the great deals. If everyone shopped like I do, the grocery stores would have to either raise prices or go out of business...
Yes, discipline. I have been shopping for staples from a once a month delivery, and at Grocery Outlet. But, this weekend, I happened on a sale flyer for my local health food store, and had 2 items that I would use unbelievably cheap. Westbrae organic canned beans for $1/can, normally these are $2.69/can. Yes, I know that cheaper beans can be bought, maybe at .69/can on sale somewhere else. But, Westbrae is a much better quality, because no pesticides, yes, but also their cans are safer and the actual quality of the beans by sight and taste are better. So, I got some, may go back for a few more, I more often eat from dried beans, lentils an awful lot and some pintos, but make home made hummus from garbanzos and like a few other ready cans for when I mess up on plans. The other item was Natures path organic cereal that was 1/2 off. So, I bought 2 of the large bulk bags, which altogether is equivalent to 5 normal sized boxes. So, because of sale is now $2/box equivalent. There are some weeks of summer where cold cereal is all I can handle, so now I have next summers cold cereal. My "impulse" buy was 2 cans of Bon Ami cleanser, as this is my main cleaning agent, so those were $1.50/each, regular priced. That is never on sale, but is still cheap and effective ( I can clean without scratching glass shower doors, glass tiles, plastic shower surrounds, as well as scour pots with one cheap product that has no bleach to bother my septic ! ) Total out the door was $23 dollars, 10 cans organic beans, 4 lbs organic gluten free cereal, 2 cans cleaner.
Back to your planning for this thread, so yes, buy a sale if it truly is what you use that is the time to stock up. Otherwise, stick to the plan. Since you have a CSA, the best may be to keep your running list on the refrigerator, of course, for those staple items you see are running low, then once you see what vegetables you have for the week, look what else you have in the pantry, plan meals around that, so add to your list a few things that will make those meals happen with those vegetables. Go to the store once a week, right after the csa delivery or next day, and stick to the list and the meal plan you have made.
