Yes there is: Most points by a player for a single team. Howe is at the top with 1809. Sid can get there. Mario is two.
Here's the other thing though, his legacy is important to him. He's talked about that a bit and how important it is to him to retire a Penguin. That is something that he can still do in Pittsburgh. What's the alternative? You trade him to...where? Everyone says Colorado but they have as many roster issues as we do. I'm not convinced they are a legit cup contender. So you trade Sid there and what happens if he doesn't win again? He still loses and now his Pittsburgh legacy is tarnished just a bit.
This is a guy who has for his entire career but team before self. You think at the end he's suddenly going to flip the script on that? Not a chance. This isn't Ray Bourque chasing his first cup at the very, very end. This isn't a guy who is going to get dump by the org ala Stammer, Kane, Toews, etc. This is a guy that's that is going out on top no matter what. There's plenty of stuff he adds to his legacy by staying.