Twenty to thirty years ago, the face value of coupons were .10 to .15 cents, but now it's rare to find a coupon as low as .25 cents. Now they are mostly .50 and $1.00.
You aren't hurting the economy when you use coupons. You're helping the economy. The store gets credit for the full amount of the sale, plus the store gets reimbursed, usually .08 cents over the full item price for taking the coupons.
The people who design, print, and deliver the coupons also earn income thanks to coupons.