When you need your customers to have an specific price on the sale, on the mobile devices you should set it at Main Menu > Settings > Orders > Discount Structure > Type > Specific Client ($) 

Main Menu > Settings

Sales orders

Discount Structure  > Type

Touch > Specific Client ($) Up to 5 Price List

Database > Clients

Select the customer, touch Price List > Select the price for that specific customer > Save

To check how it works when doing sales: Dashboard > Sell

New basket 

Select the customer

Select the product

Touch Price label to view or change the assigned price.

On the web version you should set it up, too. That is at > Settings > Sales Orders > Discount Structure > Type 

Settings > Sales Orders > Discount Structure

Type > Specific Client ($)

if you want to assign the Price List to each client you may do so on the web version at Clients > View / Edit

Select a Client 

Change the Default price A and click on the check-boxed