If you would like to show customers a reference price on your products, use the Manufacturer's Suggested Retail Price (MSRP) field and include a value that complies with Amazon's Policy on Reference Prices.
To include a reference price:
If you would like to offer a time-bound promotional discount on your product, such as a percentage discount, buy one get one free, or free shipping, you can use Promotions tools. For more information, see Promotions.
You can also show coupons on the detail page. For more information, see Create a coupon.