Your client is creating a promotional pricing discount for older-model tablets.

A tier-based discount list is a pricing strategy that applies a different discount percentage based on the quantity of the item ordered.A tier-based discount list enables you to define the tier basis type, the aggregation method, the adjustment type, the adjustment basis, the application method, and the tiered pricing rules for the discount1. By creating a tier-based discount list using the given parameters, the client can achieve the requirement of offering 10%, 15%, and 20% discounts for different quantity ranges of the older-model tablets.

References:

How Pricing Works with Tiered Pricing