When I was involved in a small bespoke tube amp manufacturing
company, we were asked by a local dealer to make up ten shielded
mains cables, for which he had been asked frequently in recent months.
The plug, socket, cable, woven screen and thick polythene outer
came to a total of Euro 10 per cable. They took only minutes to
make up, so they could have been offered to the dealer for Euro 40.
He laughed out loud, and said, "They have to be priced at Euro 400
+ VAT at least to have any credibility. The dealer price was set at
Euro 240 and he put his cut of 40% plus taxes on the top. They
were quickly sold. He subsequently found a far eastern source
(probably Euro 2 each for bulk purchase) and continued to sell these
at Euro 400.
Iain