Hmm, I guess the basic problem here is that the question can't get a uniform answer from everyone, because everyone (on both sides of the table) is approaching this with widely varying philosophies.
Many makers, at one end of the spectrum, work from the philosophical viewpoint expressed here by RJ of "I'm pricing my knives fairly based upon what they cost me in time and materials, so, no, no discount is available." At the extreme other end of the spectrum, I've heard stories (and likely so have you) about fresh-out-of-the-starting-gate makers who look around and note what the really famous and highly-sought-after makers are charging, and then price their knives in the same ballpark, figuring that's just the "going rate", without taking into account that the famous maker has "paid their dues" and they haven't yet -- some of these could stand to be taken down a notch (I don't think we have any of this latter type here). In the middle, you've got makers who figure time and materials, and a profit margin, which can vary. For them, Joe Talmadge's approach at a slow show is probably reasonable -- cut the profit margin a little in trade for making a sale that otherwise might not happen.
As well, with buyers, at one end of the spectrum, you may run into the person RJ found, who is very well off but also very cheap, who demands a substantial discount just because they figure maybe they'll get it (who knows, maybe that's how they got so wealthy), while at the other end of the spectrum is the starving student, or the person of limited means who's just really taken with a particular knife of yours. A discount here, well, maybe it just makes you go home happy knowing that the knife is in the hands of someone who will really appreciate it, or, who knows, maybe the starving student is pre-law or pre-med, and will remember that first transaction fondly and will be buying your knives by the dozen in five years.
As a prospective buyer, I don't think I'd ever initiate any sort of request for a discount -- I figure the price posted is what the maker expects for the knife, and I have to make my own decision about whether that knife is worth that much to me. I have had the experience, however, while taking some time to decide whether a certain knife (or whatever) is the one I want to take home, of the seller misreading my hesitancy as concern over the price and offering me a discount that I wasn't looking for.
(Ooh, bad grammar, I'll stop now.)
My $0.02...
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Carl /\/\/\ AKTI #A000921
Think this through with me ... Let me know your mind
Wo-oah, what I want to know ... is are you kind?
-- Hunter/Garcia, "Uncle John's Band"