We will then go into the existing template that you would like to change or maybe duplicate your existing template so you can use both (one with pricing and one without).
Go into the Edit mode on your invoice template. Find where you have your "Line Items" box on your invoice and click on "Advanced Options" this will give you an expanded view of options. The first will be "Show Prices" which you can toggle on/off depending on your preference.
After you toggle to your preference simply scroll to the top of the page and click the Check Mark to save.