Well, depends. If it truely is a great product that is rare, then it would be of benefit to mention it.
If it is some product no-one heard of because it never sold more than ten.. because it sucked.. then rare is not a good attribute (except to a collector of unusual and exotic things)
I own a "rare" phono preamp: the Audio Research PH-2. I have only seen 2 advertised on audiogon in several years, and one of them I bought! And I will probably never sell it.
It never got a review when new in any major pub in USA. and is basically forgotten and unheard. So it qualifies as "rare" IMO. Though because Audio Research is a well-known name, perhaps it doesn't meet the esoteric part of the "rare" formula?
If it is some product no-one heard of because it never sold more than ten.. because it sucked.. then rare is not a good attribute (except to a collector of unusual and exotic things)
I own a "rare" phono preamp: the Audio Research PH-2. I have only seen 2 advertised on audiogon in several years, and one of them I bought! And I will probably never sell it.
It never got a review when new in any major pub in USA. and is basically forgotten and unheard. So it qualifies as "rare" IMO. Though because Audio Research is a well-known name, perhaps it doesn't meet the esoteric part of the "rare" formula?