How much does it cost to replace power steering pump on a 2006 Chevy impala?

It depends on why the old pump failed.

The pump is going to cost between $130 and $175

The labour to change it will be between $75 and $200

If the pump failed in a way that put metal into the steering box or rack or the rack failed and damaged the pump a thorough flush will be required at a cost of over $100.00