Book, sale item gent returned in South-Western city (7)
I believe the answer is:
bristol
'city' is the definition.
(Bristol is an example)
'book sale item gent returned' is the wordplay.
'book' becomes 'b' (abbreviation for book).
'sale item' becomes 'lot' (item for sale at auction).
'gent' becomes 'sir' (a man may be addressed as sir).
'returned' is a reversal indicator.
'lot'+'sir'='lotsir'
'lotsir' written backwards gives 'ristol'.
'b'+'ristol'='BRISTOL'
'in south-western' acts as a link.
I am not very happy about this link. Some or all of it may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for bristol that I've seen before include "West of England city" , "West country port" , "West Country city" , "car" , "Place associated with fashion" .)