Your car is a tool, but it is a noisy one when the power steering starts to fail. That high-pitched groan during every turn isn't just annoying; it means the pump is struggling to move fluid. We usually see these parts fail more often in winter when the fluid is thick, but you can find better deals on labor in the late spring when shops are less slammed with heater repairs.
Negotiating the price is about the labor, not the part. Ask the mechanic for a menu price on the job before they start. Once you have a firm number for the pump and the flush, you can use a specific window of time to handle the payment.
This intro window is a deadline, not free money. If you still have a balance after those 18 months, the standard interest rate kicks in and makes this repair much more expensive than the original shop quote.