That really is the question. I can't answer it. I can give you my experience.
I am not a Coupon Queen, not even a Princess. I am more like the Court Jester.
I do use coupons. But I do NOT buy multiple papers, or purchase coupons from a clipping site. I get one Sunday paper a week and I do print some internet coupons.
The store I frequent limits the amount of items you can get, plus I do not want or need 100 sticks of deodorant.
I plan my meals from the circular, do my best to match a coupon to a sale price and limit the amount of times I go to the store. I have a baby stockpile that is good for a family of three.
Here are the stats from my latest trip:
Shoprite
277.00 before store card
252.00 after store card
165.00 after coupons(most doubled) and bag refunds (I try to match coupons with rainchecks too)
HOWEVER, no meat was on sale at Shoprite, so I spent 35.00 at another store with a good selection and decent sale prices. That brings us to 200.00 for a month. BUT I will have to buy milk once a week for 3 weeks, so add that in.
So, what I can tell you is, use the system that works for you, I use a little bit of different ideas to create my own. I do some coupons, I travel to go to the store with best prices, I shop once a month, I meal plan from the sales circular, and stock up when on sale.
Here is a picture of my receipt. I love it when it is taller than my fridge

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Adding to the pantry/stock pile. |
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I reviewed my receipt, a few coupons did not double because it would have exceeded the price of the items. I called the store and I got 4.03 in credit toward my next shopping trip |
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My Pantry. Hubby does a great job rotating stock and organizing. |