I've received a few emails about overage at Wal-Mart and Target.
Wal-Mart will give overage on a coupon as stated in their coupon policy, "If coupon value exceeds the price of the item, the excess may be given to the customer as cash or applied toward the basket purchase."
Target's coupon policy states, "Coupon amount may be reduced if it exceeds the value of the item after other discounts or coupons are applied."
So, if you have a coupon that is higher than the product price and you want to apply the excess to other items, your best bet is to use it at Wal-Mart.
Do you have a question about couponing? Email me at firstname.lastname@example.org.