It is impossible to guess at the cost to repair the camera without knowing what the problem is. Given that it has water damage, it depends on what got shorted out. I don't want to be a Pessimist but you might want to be prepared for unpleasant news. Unfortunately cameras with water damage are often not economical to repair since it would cost as much or more to repair the camera than to replace it. Hopefully the damage will be minor and the repair cheap. Let us know what the Repair Shop Estimate is. Good Luck and Enjoy your Nikons!