The price adjustments modification you can find here, let's you increase/decrease the price of a product, or products in a category, for each customer.

PrestaShop let's you give site-wide discounts to certain customers or customer groups, but it does not let you give product specific discounts for different customers. Using the price adjustments modification, you can give a different discount (or increase) for each product, to any customer you want. You can also do that on a category basis.

If you want to have wholesale prices for certain customers, this modification will help you do just that. You can enter a specific amount or percentage. The customers will only see their prices and it will be reflected in your orders as well.