save (money) on something
to save money or some amount of money on the purchase of something. I can save a lot of money on this purchase by buying it somewhere else. I am sure you can save on a new car if you shop wisely.
1. To conserve money by purchasing something at a discount: Save on all kitchen appliances during our special clearance sale!
2. To conserve some amount of money by purchasing something at a discount: I saved a dollar on my purchase by using a coupon.