Putting Opti Coat pro coatings aside, the price difference for the client between more affordable coatings should not be that big because most of the cost is in time, not product. The way I do it is I calculate the time it takes, then add product cost if it's an expensive product like a coating. If it's a cheap product I absorb the cost of the product.
So let's say I compare total cost to a client for McKee's 37 coating and CQuartz coating it would go something like this:
Washing the car about 1.5 hours
Physical decontamination using Nanoskin sponge about 30 minutes
Doing a pre-coating polish about 3 hours
Applying the coating about an hour
Total time about 6 hours
So for McKee's 37 coating I would do 6 hours @ 40$ plus about 10$ in products for a total of 250$
For CQuartz, would be 6 hours @ 40$ plus about 50$ in products for a total of 290$
So yes it would be cheaper for the customer, but not by much.
Depending how much you want to charge per hour, your prices would of course vary.