Your trade price and the 'trade' price your customer is quoted should not be the same.
Adhesive etc - I price up on a metre price and base it on either wall or floor tiling and the metres I would achieve for that particular job from a bag.
Gone are the days - IMHO - when any customer will pay the retail price for a product.
I even had a client a couple of years ago who wanted to pay cash for my labour charges
, he also wanted me to give him a 25% discount because he insinuated that I would not be declaring it so he was entitled to the Tax element:lol::lol::lol:. You have to laugh at the cheek!