Overcharge for it, free plastic (9)
I believe the answer is:
profiteer
'overcharge' is the definition.
(I've seen this before)
'for it free plastic' is the wordplay.
'for' becomes 'pro' (as in being 'pro' something).
'plastic' indicates anagramming the letters (plastic can mean easily moulded).
'it'+'free'='itfree'
'itfree' with letters rearranged gives 'fiteer'.
'pro'+'fiteer'='PROFITEER'
(Other definitions for profiteer that I've seen before include "One making excessive gains from trading" , "financial exploiter" , "Make excessive gains" , "Make money unfairly" , "killings his speciality?" .)