To answer your questions, please let us know what is wrong with the fuel pump. Is it not working at all? Is it working but the fuel flow test results were minimal? Your posting jumps right into talking about replacing the entire unit, but doesn't give us any info on how it is acting so that you or your mechanic came to that decision. If it is low flow issue caused by the internal high pressure filter, the exterior in-line filter option is significantly less costly and rather easy to do. More details please.