Yes - to set an equipment's pricing to per sample rather than per hour/day, first press edit on the selected equipment and go to the pricing tab. Leave the Internal price (hourly price) as 0, and create an instrument Add-on. Select User specified under Quantity, and then you will be able to select Per sample under Unit.
Set the price per sample, and then save the changes. Now when your user creates a booking, they can choose the add-on and input how many samples they require, and the price will be applied.
