Prius flooding ?

If the Prius is caught in a flood where water can enter the passenger cabin, that will cause significant damage:

1) The navigation system and audio amplifier units are located on the cabin floor under the front seats, so those units will definitely require replacement.

2) Residual moisture from the flooding will damage the wiring harness behind the instrument panel. Many ECUs are located there. You can expect intermittent connections which will be almost impossible to identify and repair.

If flooding is a reality in your locale, then buy the simplest, cheapest car you can find. That car is likely to be much easier to repair - or at least, you'll have less of a financial loss if the car cannot be repaired.