Im much thriftier these days, but even I make errors

So our meal planning, grocery shopping system has evolved into this: Kim and I meet once a week, sometimes in between work and errands, and sometimes later in evening after kids go to bed, and over a beverage(lastime it was Kaluha over ice, yum!) together we plan our meals for the following week. Then Kim does the grocerylist and puts it in the blog(shes much more organized that way) I price everything out because the savings and staying under budget everyweek is a great feeling for me(yes, my life has become very exciting b/c of this money saving blog!) and this system has worked for us thus far. We have found in general the best prices for groceries have come from Aldi. I know at times Costco,Sams, Walmart can match or even beat Aldi prices, but there is the issue of having to buy in big quantities that is sometimes a deterent, and for me the size of the stores and the time it takes to make my way through the store is sometimes just not appealing to me. So in general, I can buy 90% of what I need for 30-40% (or more) savings at Aldi, so it is an absolute no brainer, oh and I can whip through the store in less than 15 minutes. All that said, I made a bad purchasing call this week. I needed two red peppers for the Red Pepper Sauce, and my Aldi only had tripacks of peppers(yellow, orange and red) for $2.39(.80) per pepper, and instead of purchasing those and finding another use for the yellow and orange peppers, I opted to purchase peppers at local grocery store since I needed a few other items for the dinners this week that Aldi didnt carry. Well, I ended up buying 2 red peppers for $4.59. I was mad at myself the whole way home from the store, and eventually went back to the store, returned the peppers, went back to Aldi and bought 6 peppers for less then $5.00. As far as the extra yellow and orange peppers- they will not be going t waste, I am roasting them and topping them on crostini for part of our Easter Meal.