If you add a products to be sold by quantity with the predefined list of quantity options, then you can use the bulk discount option to set up the pricing for each quantity. In the Neartail Edit page, click on the Add product icon > enter the product name in the title option > select Sold by quantity > 1, 2, 3, 4, 5 will be added as the default quantity options > enter $4.75 as the product price > click on the gear icon for this product > Product settings will be displayed > click on the Bulk discount option > enter $20 as the price for 5 and click Save.