Penny I invested in bust we chose, artwork on display (9)
I believe the answer is:
showpiece
'artwork on display' is the definition.
(piece of work shown in a display)
'penny i invested in bust we chose' is the wordplay.
'penny' becomes 'p' (short for pence).
'invested in' is an insertion indicator.
'bust' is an anagram indicator.
'p'+'i'='pi'
'we'+'chose'='wechose'
'wechose' anagrammed gives 'showece'.
'pi' going into 'showece' is 'SHOWPIECE'.
(Other definitions for showpiece that I've seen before include "Impressive exhibit" , "flagship" , "especially fine example" , "shining example" , "good example" .)