Exploiting the public

Recently I wanted to buy a PCV valve diaphragm for my car.Since my car uses a universal type of diaphragm,I contacted various car part agents.Across the board I was told that they do not sell it loose,but you have to buy the rocker cover containing this diaphragm too. I regard this as a total rip off and am extremely upset by the fact that I had to pay more than R 3 000 to get a diaphragm,which, if sold separately, would have cost about R 700, including shipping, if I was able to order it on line from overseas. Unfortunately these companies do not to South Africa. As far as I am concerned,this is exploitation of the public in the worst degree.