The thing about it is, if I am working on a grill and something comes up. An endcap this toast, a lid that was cracked you didn't notice. A thermometer that doesn't work, a drip tray that is worse than you thought, a missing bolt, screw, end cap, clip, whatever, I don't have to put my build on hold waiting to acquire another part. I know that if I pick up a Silver B or a Genesis 1000, it doesn't matter if the left table is cracked or the drip pan is rotted out, or the fire box has a huge bulge in it. I know I could take it home and rebuild it immediately.
I remember back my first couple years of doing rehabs. I was constantly scrounging for parts. Everything from lid hing pins to control panels and wheels. That is no longer an issue. And, when I have more spares than I need, I don't mind shipping a part or two off for a couple extra bucks to someone who is up against the wall on a rehab.
Do I suggest this for the guy that just wants to do one or two grills, heck no, but I am sure Dave, Jon, Stefan and some of the other rehabbers know what I am talking about.