Of all the parts on our cars that are bought and sold on the used market HPFP bits is not one I would ever try and save a few dollars on. Spend the money, get the warranty and do the job correctly and all is well. Not to mention the people scamming folks on some of the forums and FB.
Hell, I struggle with why anyone would waste the time to swap pump bits prior to selling the car. Leave them in and move on, there are other parts worth swapping if you have OEM parts handy.