My 2 Cents...
I agree that it's not good to give out prices etc....BUT, any idiot can go online to ANY search engine, and type in the brand name and model# and get our prices (sometimes cheaper). This is not new guys. We deal with a lot of A/D/S in-wall speakers and a client once told us that he could get them cheaper online. My boss told him he was a lier, because my boss was selling them for the cheapest A/D/S would allow him to. I did a little search online and found a company in California that was selling the speakers for about $10 over my bosses cost. The only thing you can do is try to get these companies to stop screwing us over. We contacted A/D/S and supplied them with the web site, and they are hoping to find out who is supplying them with the speakers and put an end to it. Same goes with the Prontos, I can find those online for cheaper than I can buy them for. I bet Philips would try to do something about that if they were notified. The only thing we can do is tell the clients we will not install ANYTHING that we don't supply ourselves. And, if we do install it then there is absolutely NO warrenty. I personally try to do whatever I can for as cheap as I can because I don't make much money at all (especially for living in Massachussetts), so I don't see anything wrong with what Carl is doing as long as he does it himself from start to end.
Just my 2 pennies