VCT soldenoid and camshaft phaser
 

I don't really know a whole lot about cars but my 04 F150 keeps stalling when I come to a stop. Brought in to dealership and they say I need a new "vct solenoid and camshaft phaser" for a cool $1200 bucks. The truck has just under 100k miles. Are there any other forseable reasons why the truck is doing this? That's a lot of money and I need to know if they're trying to screw me over.

Much obligied.

-John.