Edible seed, many of which would yield paltry sum (6)
I believe the answer is:
peanut
'edible seed many of which would yield paltry sum' is the definition.
'peanut' can be an answer for 'edible seed' (I've seen this before). I am unsure of the remainder of the definition.
'edible seed many of' is the wordplay.
'edible seed' becomes 'pea' (I've seen this before).
'many of' becomes 'nut' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'pea'+'nut'='PEANUT'
Can you help me to learn more?
(Other definitions for peanut that I've seen before include "Edible seed of a leguminous plant" , "Popular edible seed, often salted" , "foodstuff" , "butter ingredient" , "Ante up for the popular kernel" .)