Good tips as long as you still have some control. None of my vendors for network components will even talk to my clients so they're not a problem. It's when people get quotes from consumer oriented computer stores and I'm forced to explain the difference in the quality of the components it gets time consuming.
In the case of the $16,000 Joomla site, none of the players knew what they were getting until it was delivered. I'm not going to make any friends pointing out that they just got taken to the cleaners. I just moved on.