Cost of oil change

I just asked some fFh’s, which costs an oil change for the 2.0 TDCi. all gave me the information by phone “you pay no wage costs, only the pure material.” although the owners are all in the unmittelbaren circle, the price fluctuates however between 78,00 and 95,00 euro. the question is, why is the oil with filter so expensive. does this oil have a special specification, or is the filter something special? besides, I ask myself, what is the one workshop for he takes more material, which the other workshop forgets that there are different prices for one and the same work. all owners spoke of 6ltr oil, so it can’t be because of it. otherwise he might have thought that one takes less oil than the other. :-))