Is it smart to use

I like some older "vintage" amplifiers and of course old stock tubes. While purusing the amps on epray vintage amps section, I often see rare which to me sounds like a big headache if it needs repair. Many are so obscure that the advertiser does not know what it is. They use RARE as a truly important positive attribute, maybe for a misprinted stamp but an amp?
I think it would only be special as a rare variant of a famous make or model. Also for those that put these units on display as a collectable. I use everything I buy. What do think about using RARE other than for a super prime great steak.
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?
Remember in the words of 'epray' some /many of the sellers are not aware of what they have - every listened to a Hadley amp? Having said this, If you know the amp, or MFG, and have a high interest or opinion of the product try it out, there are some gems out there. On the other hand, Elizabeth correctly identifies some rare components as being rare for a good reason.