If you do that - which is the true cost to you - the example has quite a different result as I showed you, reducing the $100 cost down to $85.56. You seem to not understand that ... or not wish to.
No, because my original example was $100, before any tax was added. I'm glad you've overcome your fear.
You seem to not wish to know what the cost (as opposed to price at point of sale)
I was asking specifically about the price at point of sale.