No offence but asking people here how much repairs are going to cost you is a little pointless. Why not just goto Apple and ask them and they can tell you directly. If you are trying to hide the fact that you spilled water on it, and get them to fix it under warranty dont bother, liquid damage is pretty obvious and there are special sensors built into the computer similar to the iPhone to change colour if liquid comes into contact with it. Just goto the Apple store and get the keyboard replaced, the manager could be nice and list the repair as under warranty but you will most likely have to pay out of pocket.