Outline cost initially, before working trip (7)
I believe the answer is:
contour
'outline' is the definition.
(contouring is a kind of outlining)
'cost initially before working trip' is the wordplay.
'initially' indicates taking the first letters.
'before' is a charade indicator (letters next to each other).
'working' becomes 'on'.
'trip' becomes 'tour' (I've seen this before).
The initial letter of 'cost' is 'c'.
'c'+'on'+'tour'='CONTOUR'
(Other definitions for contour that I've seen before include "Feature on map" , "Outline (of land)" , "Outline, profile" , "Map line of equal altitude" , "Silhouette" .)