Reportedly purchase commodity generating side effect (2-7)
I believe the answer is:
by-product
'side effect' is the definition.
(thesaurus)
'reportedly purchase commodity' is the wordplay.
'reportedly' shows a homophone (sound like).
'purchase' becomes 'buy' (buy is a kind of purchase).
'commodity' becomes 'product' (product is a kind of commodity).
'buy' sounds like 'by'.
'by'+'product'='BY-PRODUCT'
'generating' acts as a link.
(Other definitions for by-product that I've seen before include "Secondary, sometimes unintended, result" , "Spin-off" , "Incidental result of manufacture" , "Extra result" , "Side effect" .)