IF you think it actually needs the CAMSHAFT position sensor it will be about the same cost as to just let the repair shop install their part! That way you have a little warranty! Most shops need to make a certain amount on every job, so if you have your own part and the shop needs to make a profit of, lets say $15.00 on the part, you pay that amount as well as the labor, that is just how it is and has been for years! I love it when folks bring in their own parts cause if that aint the problem then i am in the clear. Or if the part fails i am still in the clear. How much would McDonalds charge you to cook your own hamberger meat? Then if it taste like crap, not much you can say! Not much to be saved here by buying your own part as it's not that much to start with. I hope you see what i mean.
Cam sensor is no big deal to replace but it likely has not failed. What goes wrong is the magnet that the sensor senses needs replacement or the timing chain and gears are worn out. Much bigger job than a sensor. And I agree with pushrod .....reputable shops suppy the parts, skill and knowlege to repair cars.