Having an auto repair shop replace a power steering pump costs from $400.00 to $500.00 and in some cases can be as high as $1,000.00 depending on make and model of vehicle and how hard the power steering pump is to get at.
If you know what you're doing then you can save money by replacing the power steering pump yourself and if you do replace the power steering pump yourself you can do so for the cost of the power steering pump which varies from vehicle to vehicle.
You should be able to replace the power steering pump for around $100.00 to $200.00 which is what some power steering pumps cost.