If you wish to update the price linked to your stock you can do this quite simply by accessing the stock section within Phorest under Manager > Stock. 

Next you will need to double click on the item of stock. When you have done this you should see a screen similar to the below. 

Within this section you can update the Sale Price to match your new pricing.

To update the price simply click on the calculator icon next to the price displayed.

When you have the updated price entered select OK and then hit Save in the bottom right hand side of the screen to confirm the changes made.