Water pump replacement

My 4runner has 90K miles and I'm having the timing belt replaced. Should I also have the water pump replaced while the shop is replacing the timing belt for preventative maintenance? I'll save about $150-$200 in labor but I'm not sure how long water pumps last.

I have a '99 4runner V6 4x4 and will probably keep it anouther 3-4 years.

Thanks for your suggestions.
Jeff

Most people replace the water pump at the same time.

Well since your doing the timing belt anyway and you can affod to do the water pump at the same time, you may as well do it. I have seen water pumps last well up and over 200k but hey they can be a pain to replace on their own.

At least you'll know it won't go on you if you replace it now.