New picture frames charged firstly at a reduced rate (3-5)
I believe the answer is:
cut-price
'at a reduced rate' is the definition.
'new picture frames charged firstly' is the wordplay.
'new' indicates an anagram.
'frames' means one lot of letters goes inside another.
'firstly' suggests taking the first letters.
The first letter of 'charged' is 'c'.
'picture' with letters rearranged gives 'cutprie'.
'cutprie' enclosing 'c' is 'CUT-PRICE'.
(Other definitions for cut-price that I've seen before include "At reduced cost" , "At a much reduced rate" .)