I think a lot of employers ask for someone with expertise in several areas figuring, if they get a response from someone with all that experience - thats great, otherwise they can pick from the best of the responses.

Sounds similar to common practice when selling a car or a home. If you ask for a bit more than you expect you will have to settle for and get it, you come out ahead. Otherwise, you probably get what you really expected to receive and the other guy thinks he got a deal.

My .02