It may be a common belief or even a common approach in certain business situations - such as buying a used car or a low to mid-market house - but as an approach to a more sophisticated "prospective seller" the approach would likely be received as being somewhere between "juvenile nonsense" and just plain offensive - like "Does this (?) really think I'm that () or that he's that ()"? More sophisticated players know their numbers, know their target operator, know whether that operator knows their numbers, etc.
Now, put this in context. In a domain transaction whom do you think is the more sophisticated operator: The person who snagged a domain in 1995, 1997, etc. or the person who is looking to buy it in 2007 but who can't name a price from the outset? In this context I'd suggest that you show some grasp of the situation . . and some respect, as it's the only approach reasonably calculated to work.
I was able to make some deals with very "difficult to reach" people only by virtue of showing respect, the respect of making an educated offer from the outset. It wasn't that I knew this from the start. If only I was that smart. I learned the hard way and early on blew a few opportunities to possibly make a deal. When it comes to taking the wrong approach to dealmaking you soon learn that some doors, once closed in your face, will simply not open again. Sophisticated domainers need my money about as much as they need the aggravation of dealing with an unsophisticated buyer - "me", at that time.
Folks need to tune into reality if they are going to make a pitch for a quality domain. You are not buying a used car from a used car dealer, someone who needs to make a sale so he can pay his rent for his used car lot. Far more often than not, with prime domains you are dealing with a sophisticated business person. So, get a good offer number worked out and make your offer.
Otherwise your email - the one about buying a domain - will be deleted without the recipient ever opening it.
[edited by: Webwork at 4:16 am (utc) on June 14, 2007]