Mini2 water damage

Flew too low and me dog managed to knock it out of flight and onto the beach. Waves tumbled it before I can retrieve it. I’m looking at definite water damage.

Turned it off and didn’t touch it for weeks. Definitely hear sand in there still and the prop notes are hard to turn, gimbal seems stuck.

Done unit senses the battery but won’t go into power on/sync mode.

My DJI refresh says unavailable, have had it since ‘21

What are my best options? I’m assuming turning it in for repair would charge me the full replacement cost?

Otherwise, I’m looking at a 4k mini for around the same price. Would the controller/batteries be swappable?