Pragmatist retails badly (7)
I believe the answer is:
realist
'pragmatist' is the definition.
(I've seen this before)
'retails badly' is the wordplay.
'badly' indicates anagramming the letters (letters in the wrong order).
'retails' is an anagram of 'REALIST'.
(Other definitions for realist that I've seen before include "Retails like practical person" , "One who sees things in a practical way" , "Someone who's pragmatic" , "Writer like Balzac" , "One with a pragmatic attitude" .)