HiYou need to go in independent shop and try and sell some tiles, then you see what they are willing to pay
Iv done that to and the results were promising as long as they could get to them when they need without keeping stock them self and I can do that..
So what I’m gathering and as my suspicions were.. there are not set prices / industry mark ups etc and it’s basically what ever you can get away with, not very good. One Independent that buys from a big name said even if he got the tiles cheaper from me he would not sell them cheaper then he already does (£70-90 m2 for 60x30) as his customers in his area liked/wanted to pay it and would associate cheap tiles with poor quality which is not always true.