can i sell back to you my water damaged phone

Apple may give you its market value if you submit it into their recycling program and they run one in your country.

(109297)

Yes, I will pay you 5 dollars for it.

Can you sell it back to who? You're not talking to Apple here. These are user to user forums, so I'm not sure why you would even ask that question here...

Can you sell your crashed and damaged car back to your car dealer?

Most likely apple will not take the phone and give you money for it since water damage violates the warranty