This is really an appendix to the other two parts (one and two) of this series.
Only the players' opinions matter
In other words, only the players determine if they are interested or not. All the GM description in the word, all the clues, all the signals - it doesn't matter. Treasure that interests the players is interesting.
You can't always predict what that will be. You can try - the "clue forward" approach I mentioned last time is at best a strong signal.
You can even go as far as writing out the description and printing it out, attaching a picture, and handing it to the players and say "This is important and interesting!" but it won't guarantee they are actually interested. They still might not care.
And that's fine. The goal is to make it possible for a treasure to be interesting for more than its sale value, but you can make it so anyone cares. If you do all the tricks I mentioned last time and they still write "comb, 1500" on their sheet, so be it. Let it go and move on, and try a different item or a different approach next time.