Okay hear me out-
First of all, are you bearing the cost or are you passing it on to the customer? If you pass it on then labor is the predominant issue.
If you do not pass cost on, then here is where it can save you bucks:
The polish is roughly twice as spendy but lets say lasts 3x as long. You don't have to reapply it for two wash/wax cycles and collect your usual fee. Maybe you touch it up with QD+. On top of that you save labor which is also important in calculating your overall cost.