Collector's item's a bloody state, I suppose! (6)
I believe the answer is:
rarity
'collector's item's' is the definition.
(I've seen this before)
'a bloody state i suppose' is the wordplay.
I cannot really understand how this works, but
'a' is within the answer.
'state' could be 'ri' (Rhode Island abbreviation) and 'ri' is found within the answer.
This may be the basis of the clue (or it may be nonsense).
(Other definitions for rarity that I've seen before include "Unlikely event" , "I tarry (anag.)" , "Unusual thing" , "Curiosity, singularity" , "wonder" .)