Possible Clues:

• Farewells
• Parting words
• Waves often accompany them
• Things people are going to say?
• Farewells ... or, homophonically and read top to bottom, what the first words of the answers to starred clues represent?
• Opposite of hellos
• Do they sound fair? Well, they're the last thing you'd say
• They're going as bargains, by the sound of it
• Bargains, by the sound of them, when they're going