When adding a Supply Detail to a Function (see related article), the system will automatically check to see if there is a Price associated to the Supply (from the main list of Supplies). If a Price exists, it will display in a grayed out box and you will see an option to 'Override' the Price manually.
NOTE: When using the 'Override' option, the 'Quantity' entered will not automatically calculate the 'Actual Price' because you are manually editing the field. For example, you may receive a $25 discount when renting 2 x Projection Monitor - 32".