Fell for bargain (5-4)
I believe the answer is:
knock down
'fell' is the definition.
(I've seen this before)
I don't understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for knock down that I've seen before include "Fell - to this bargain price?" , "Cheap - floor" , "Declare (lot) sold" , "aim of Haye, say" , "very low in price" .)