If he doesn't opt out, he's due 4/80. Maybe bumping him to 6/150 gets it done?
Seager got 10 years, but was only 28 at the start of the deal. He was the only $200M+ deal last winter. I don't believe Xander will go for that much.
Semien got 7/175 for age 31. Seems like a better comp if not too high considering that Story/Baez both got 6/140?