The cost to replace a windshield wiper fluid motor or windshield washer pump is around $90.00 to $225.00 for parts and labor.
The cost of replacing the windshield wiper fluid motor can vary from vehicle to vehicle and if it's easier to change out it will take less time and cost less.
If you're up to replacing the windshield wiper fluid motor yourself you can do so for around $50.00 to $100.00 and your time.
You can buy the tank along with the wiper fluid motor online and they are pretty easy to replace.
However if you have to have a shop replace it then you should expect to pay around $100.00 to $225.00 depending on the vehicle.
A mobile mechanic or other local shop or local mechanic can also replace the windshield wiper motor and it will be cheaper than a dealership.
Dealerships charge more for parts and labor to replace parts and so it's best to use a local auto shop instead of the dealership.