Yes they are expensive. I got lucky and found this one on Kijiji. The aftermarket ones just aren't the same, but they do the same job. I wanted it to keep stuff out of the bed and still out of sight. The Bak Flip cover came from Kijiji as did a Bedrug.
Pic-N-Pull supplied a replacement header heat shield (I was missing one), windshield washer fluid reservoir (mine sprung a leak) and a driver side power window assembly (my cable broke).
I just did new rotors and pads on the rear. Had a little issue with getting the right parts as most places don't list the C3. Really really wanted to paint the calipers but just didn't have the time to do it properly. Maybe when I do the front brakes. Also did the U joints on the front shaft. Had to go to GM for those.
Then, because I had to, gave the truck a new set Cooper Discoverer AT/W tires - a sort of all terrain winter hybrid. E rated but lower tire pressure than the BFG's. Already noticed the smoother ride. No solid centre rib and all tread blocks are sipped. They weren't what I wanted but the price was great so they will do for now. Snowed a couple days after the install and so far so good.