Parts are pretty expensive, so it pays to shop around.

 Here's a tip:  Always check with the dealer -you'll be surprised how many times you can beat the parts house price.

The first time I saw that anomaly was in 1983... I was working on a Nissan pickup and needed an oil pressure sending unit.

At the dealer:  $2.45

At the parts house:  $8.00

Here's another one:

A/C suction/discharge line for a Chevy pickup:  

At the parts house:  $180

At the dealer:  $44

One more:

A belt tensioner for my 1995 Taurus:  At the parts house:  a DAYCO tensioner was $79

At the Ford dealer:  $51 

The DAYCO part didn't last a year before the pulley was out of line and throwing the belt.

Words to the wise - I could go on and on about this; always check with the dealer for parts prices!