Fish product for a buck, perhaps (3)
I believe the answer is:
roe
This clue might be a double definition.
'fish product' is the first definition.
(fish eggs)
'buck perhaps' is the second definition.
'roe' can be an answer for 'buck' (thesaurus). I'm not certain of the 'perhaps' bit.
'for a' is the link.
Can you help me to learn more?
(Other definitions for roe that I've seen before include "Part of fish, sounds like go through water" , "Fish eggs; small deer" , "Swift runner" , "Caviar" , "shy animal" .)