Selling for 50K off the market price of a non flooded car is not realistic.

You could try it though.
I know of an owner of a 2007 Civic FD 1.8S A/T. Car was fully submerged but fully repaired and restored by Honda Casa. Owner sold it for "only" Php 250K. Now, I think the fair market value of such vehicle should be more or less Php 650K.
Ps: Nobody can really say that a car that has been restored due to the flood, can actually better than its previous condition. Problems will crop up as the vehicle is used.