Thats what I ended up doing, the valves 4 of them only cost a buck for all so I just put them in. Told the cust he needed them. No problem. Actually I needed them more but that's how it goes.
Gave my little speech to install, I don't think they got it or gave a $hit. Since they are so cheap I might stock a few on my truck just in case. I try to think of the next guy as much as possible, I just don't think some of our install guys give a crap. "Leave it for service they will take care of it." Thats kinda frustrating.