How much does it cost to have a water pump replaced on a Mercury Capri?

Call your local parts store.

I paid $490 to have the water pump replaced.

FInd a mechanic. I just had a water pump installed in my Capri and while they're doing that, make sure they put a new timing belt in, because if you have a 91 Turbo w/ ac, it's a 4.5 hour job...

water pumps are fairly cheap ,,, i got mine on eBay brand new for £24

fxcking loads!