Extortionate price foolish brother gayly bid (8,7)
I believe the answer is:
daylight robbery
'extortionate price' is the definition.
'foolish brother gayly bid' is the wordplay.
'foolish' indicates an anagram.
'brother'+'gayly'+'bid'='brothergaylybid'
'brothergaylybid' with letters rearranged gives 'DAYLIGHT ROBBERY'.
(Other definitions for daylight robbery that I've seen before include "as shoplifting usually is" , "Blatant overcharging" , "Extortion" , "Scandalous" , "A shameless swindle" .)