Let's say you've got Event Staff booked for 55.00 per hour for a minimum of 8 hours.
If booked longer, their rate increases 1.5x for each additional hour.

First, create the service in your inventory and ensure the pricing is set to hourly.

Then, we'll need to add the minimum time booked (8 hours) and the total cost ($55 x 8 = $440).
Next, add the higher rate for the additional hours. $55.00 x 1.5 = $82.5. For an additional 8 hours, that would come to $660.00

Finally, on a project, if we add the item for 9 hours, we'll see the rate correctly calculated to $522.50.