It is not how much you save but how much you pay.
To illustrate this point – I used to sell and install vinyl replacement windows. I had a hard time selling a window for $100.00. So I marked the window up to $200.00 and created a price list. Then I would show the customer the price list and offer a discount. This improved sales and customers were elated at their “savings” and the great deal they got.
A local window company runs a half-off or buy one and get one free for a limited time almost continuously. Another example was when I tried to buy a tire at Kmart at Wednesday’s sale price on a Thursday. The manager refused the sale price but told me to come in the next Wednesday because it goes on sale every Wednesday.