I just recieved a quote of $430 to change a fuel pressure regulator. This is way too much if you ask me, to install a $40 part. Does anyone know if this is really labor intensive, or am I being taken to the cleaners?

Ask to see their Chilton labor guide. It should give an approx time to properly make the repair and should not charge for more time than what the guide says even if it takes them longer due to in-experience.