Collector's item (6)
'collector's item' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for rarity that I've seen before include "Something unusual, perhaps collectible" , "Collector's item" , "wonder" , "Something very scarce and often valuable" , "Unlikely event" .)
'collector's item?' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Another definition for repo that I've seen is " Type of deal".)