Pub to profit from good deal (7)
I believe the answer is:
bargain
'good deal' is the definition.
'pub to profit' is the wordplay.
'pub' becomes 'bar' (I've seen this before).
'to profit' becomes 'gain' ('gain' can be a synonym of 'profit').
'bar'+'gain'='BARGAIN'
'from' acts as a link.
(Other definitions for bargain that I've seen before include "Count on" , "Cheap purchase" , "Agreement; cheap item" , "Great deal!" , "An agreement, or thing got cheaply" .)