Good Store Coffee; Social Stuff

Here is a little struggle I have. If Good Store sends me a 20% off code (SUMMER) for their coffee/tea; and I buy the 5-pound bag of coffee, which is a considerable savings per ounce over the 12-ounce bags (5 pounds, which is 80 ounces, costs approximately the same as two-and-three-quarters 12-ounce bags, or 33 ounces; it’s $.86/ounce vs $2.08/ounce); and I use my “dots” (little reward points that accumulate from purchases) to get free shipping; and of course I got the 20% off as well; then am I really doing much good? I saved so much on the order, I’m not sure there was any profit left to go to the good cause. What is the point of me “shopping to benefit charity” if I am going to reduce the charitable aspect as much as I possibly can? But…I would not have placed the order without those discounts (at a certain price, I start thinking I should just buy my usual grocery-store coffee and send a check to the charity), and I am a shopper who is much more likely to keep shopping at a store…