This article addresses custom pricing in the Gateway and how this is submitted to your customers
In your Gateway account you will have to list a default price for all products, but you can also then list custom pricing for each customer if your pricing varies. If no custom pricing is assigned then your customers will receive the default price automatically when you submit a Price List, but if there's a listed custom price then this is what will send to the customer.
You may find that you've imported a price file with one price, but when you submit this through to your customer they are still receiving an old price file. This is most likely because you have previously assigned them custom pricing.
You can see this in the system if you:
- View a product. In Catalogue > Products > Actions > View, select the Customers tab to see if you have any Custom Prices listed for any customers. 
- Send a Price List. Just before you submit the Price List to your customers you'll be able to review the listing in the 'Edit before send' tab, this will show if any custom pricing is going to be sent. In the below example the default price for the Demo Product 1 is £5, but the 2 customers will be receiving £4.85 and £4.50 as per the Custom Pricing set up for this product.
Whenever you're sending a Price List look out for this 'Warning: Individual prices include' message. If you need to amend a price for a particular customer at this point you can do at this point by simply updating in the box on the right-hand side, just don't forget to Save changes before you Send to Customer
You can list custom pricing for all customers in one go whenever you load a price file into the Gateway account with a product import. Just add a column to the usual product import format for each customer and then map the columns to the customer using the import wizard.
So you can add columns like so to the import spreadsheet: 
Then when you import, you can map these to the appropriate customer in Step 3 by clicking on the Custom Prices tab and selecting the appropriate column names from the dropdown to map to each customer. 
Once you've done this continue with the Import as usual, when creating the Price Lists you'll see your custom pricing sending to the customers selected as required.