You can go to
www.napaonline.com and get the prices that you should be paying.
Having worked in independent and NAPA parts houses in the past I can tell you that they all either do or can sell off different price sheets and a lot of NAPA stores do sell to the general public at full list.
The
www.schucks.com or other O'Reilly sites will usually show really competitive prices and give you a good idea of what a real deal is.
www.northernautoparts.com is another one to check. I buy a lot of hard parts from them and have been really happy with what I got.
But as others said, factor shipping in to the equation. If you can't get it shipped to the door with a total of less than the local guys charge it isn't a deal.