It's going to be a tough call. Spencer has become an excellent pressure player to complement Ware. Those type of guys are very hard to find. There is no guarantee that replacing Spencer with a draft pick or signing somebosy else can do what Spencer can do.
Age is an issue. But he does have 3-4 productive years left.
I prefer Spencer stays, but the contract has to work. He counts almost $9M this year. If we can sign him long term that can count $7M-$8M a year for 3-4 years, it is doable.
I don't know if that can be enough to keep him. He can get big money elsewhere. It will depend on if he wants to remain a Cowboy or not.