Water Pump Question

[MNICEBOX]

Wondering what the consensus is on replacing a water pump @ 64,000 mi (2003 S) as part of preventative maintenance. No current noises or leaks from the pump. It's not cheap (pump alone is $250-$400 , plus the thermostat which will be done at the same time), but neither is the impact of broken impeller blades in the motor.

I've read the DIY guides on replacement- is this more than a 2/3 wrench job - the most ambitious DIY I've done on the car so far are rotors/pads, swapping a larger throttle body and intake and installation of an IMS Guardian (PITA).

Thanks.

Steve