I'll begin this post by saying that Sid is absolutely not going anywhere.
As an academic exercise though, what do you think he'd fetch in this insane sellers market? Something like two firsts, a second, a top prospect, a mid prospect, and maybe a lottery ticket player or two (or maybe some later round picks)?
One, you're never getting close to his value, even at age 37.
Two, the only way to get the maximum return - even recognizing it'll still fall short of his value - is to do it when there are the most number of potential suitors. That's not now, with everyone pressed up against the cap and trying to squeeze every last penny. Sid's not prohibitively expensive, but he still carries a decent cap hit.
So despite this being a major seller's market, it's the worst time to hypothetically trade a player like him. He's not Ray Bourque, trying to win that elusive Cup, so time isn't really of the essence either.
That makes this a draft day/offseason deal, when teams have more flexibility.
Also, any team he'd be hypothetically interested in would have to be a contender. So that diminishes the value of the first round picks, because they'd likely be late first rounders.
I think the haul has to be something like:
No. 1 prospect
No. 2 prospect
First round pick
Above average roster player
So, hypothetically, if it's Colorado then the haul includes Cal Ritchie, Mikhail Gulyayev, Casey Mittelstadt, and a first round pick.
Some will say that's too much. Some will say that's not enough. And that's why you don't trade Sid. No one will be happy.