Surprisingly cheap gold headwear (7)
I believe the answer is:
chapeau
'headwear' is the definition.
(archaic term for a hat)
'surprisingly cheap gold' is the wordplay.
'surprisingly' indicates anagramming the letters.
'gold' becomes 'Au' (Au is the chemical symbol for gold).
'cheap' is an anagram of 'chape'.
'chape'+'au'='CHAPEAU'
(Other definitions for chapeau that I've seen before include "(French) hat" , "Cap (French or heraldic?)" , "Fashionable hat" , "something to put on noodles" .)