I’ve owned 35+ pairs of speakers over the last 11 years. About half were either pre-owned or dealer demos.
I’ve had both positive and negative experiences buying used, but also a couple bad experiences with new speakers as well.
One thing I’ve come to conclude is that one seller’s “7/10” condition speaker might be a 9/10 (allegedly) in the eyes of other sellers. This seems to be ever more prevalent in the post-Covid era. I can’t count how many times I’ve see a pre-owned speaker listed as a “9/10” when it’s obvious to me that the drivers were abused, such as tweeter domes with ripples or dimples (very common with Dynaudio tweeters for example).