Complain as book price rises (4)
I believe the answer is:
beef
'complain' is the definition.
(beefing is a kind of complaining)
'book price rises' is the wordplay.
'book' becomes 'b'.
'price' becomes 'fee' (I've seen this in other clues).
'rises' is a reversal indicator.
'fee' in reverse letter order is 'eef'.
'b'+'eef'='BEEF'
'as' acts as a link.
(Other definitions for beef that I've seen before include "Small errand" , "nickname of US State" , "Grumble - muscle" , "Complaint; strength" , "Meat of the cow" .)