The cost of arranging (incl. composing) an instrumental song.
The cost of arranging (incl. composing) a vocal song.
The cost of makting scores and arranging the music on the sheet music.
The cost of recording vocals and live instruments.
The cost of pitch and timing correction, mixing and mastering.
The cost of arranging singers and singing lead vocal, chorus, etc.
The cost of arranging players and playing musical instruments.