Purchase tops for girl resplendent in pink (4)
I believe the answer is:
grip
'purchase' is the definition.
(I've seen this before)
'tops for girl resplendent in pink' is the wordplay.
'tops for' says to take the initial letters (in a down clue, the tops are the top letters).
The first letters of 'girl resplendent in pink' is 'GRIP'.
(Other definitions for grip that I've seen before include "item of baggage" , "one on film set" , "Clutch - holdall" , "Engage" , "studio assistant" .)