The other thing that probably inhibits demand is many pipe smokers don't like stingers.
Perhaps. But that can go the other way, too. Collectors, as opposed to smokers only, likely want the stingers. As a constant Kaywoodie hunter I find it amazing that many listings do not mention or show the stinger. I know I have not bid on many a pipe just because I have found that if this datum is not posted it is likely the seller hasn't a clue. Too many times I have "asked a question" of the seller and then had to explain what a stinger is.
Over the past four or five years of Ebay cruising I see many KWs relisted several times, unsold for various reasons - stinger questions probably among them.
They are easy to cut off so that should not affect a bid if one wants a pipe. But they are impossible to put back on and once cut it's cut forever.
And then with Kaywoodies the style and dating of the stinger gets involved.
Lately I have been trying to replace my lost #7713...for less than $100.00. Good luck with that.