Cost of installing a water pump

Depends on who does it. I recently did mine myself for $150 by buying a gates timing belt kit that included the water pump. Had I bought the same parts through my local Hyundai shop the parts would have been over $650 and the labor to do it another $680. Here is the guide I used to do it myself: https://www.youtube.com/watch?v=2Da2qtf1KJk