Shoot for a bargain, sweetheart! (5)
I believe the answer is:
snipe
'shoot' is the definition.
(I've seen this before)
'a bargain sweetheart' is the wordplay.
'a bargain' becomes 'snip' (slang term for a good deal).
'sweetheart' becomes 'e' (the heart/centre of 'sweet'**).
'snip'+'e'='SNIPE'
'for' is the link.
(Other definitions for snipe that I've seen before include "Wading bird with long straight bill" , "Pines for bog bird" , "Game bird" , "Verbal criticism" , "The bird to shoot from cover" .)