Hope,
My personal experience is that some more high-priced domains get a lot of "touchy-feely" offers at $60 so they can see your "counter offer" and then decide what to do from there. Of course, I won't accept the $60 offer for some domains, and I respond with the message that their first bid needs to be legit (No need to show my hand too early). So, in short, "make an offer" on excellent domains does get more offers than setting a price, but I don't necessarily know that it's a good thing.
On lower priced names, I have had better success setting a price, but still allowing the user to make an offer that's lower than that and then negotiating from that point.
-Allan