Sting reduced concert attendance, raising cost (5,3)
I believe the answer is:
price tag
'cost' is the definition.
(I've seen this in another clue)
'sting reduced concert attendance raising' is the wordplay.
'sting' becomes 'pri' (I am not sure about this - if you are sure you should believe this answer much more).
'reduced' indicates taking the first letters (the word is reduced to its first letter).
'attendance' becomes 'gate' (I've seen this before).
'raising' says the letters should be written in reverse (in a down clue, letters go up).
The first letter of 'concert' is 'c'.
'gate' written backwards gives 'etag'.
'pri'+'c'+'etag'='PRICE TAG'
Can you help me to learn more?
(Other definitions for price tag that I've seen before include "shows outlay required" , "Shop goods label" , "Indication of cost" , "Amount to be paid" , "Label showing cost" .)