What you must pay great pianist heard on piano with lyricist (4,5)
I believe the answer is:
list price
'what you must pay' is the definition.
(price you must pay)
'great pianist heard on piano with lyricist' is the wordplay.
'great pianist' becomes 'Liszt' (Franz Liszt, p8pp-p886).
'heard' indicates a 'sounds like' (homophone) clue.
'on piano' becomes 'p' (musical abbreviation. I am not sure about the 'on' bit.).
'with' means one lot of letters go next to another.
'lyricist' becomes 'Rice' (Sir Tim Rice).
'liszt' sounds like 'list'.
'list'+'p'+'rice'='LIST-PRICE'
(Other definitions for list price that I've seen before include "RRP" , "What manufacturer says is the cost of an item" .)