I’m going to disagree that any NS buyout right would be at a price set by seller. These are 2 highly sophisticated parties and that’s arguably an unreasonable term. More likely the buyout price, if the agreement included a buyout, would be set by a formula based on business metrics and that formula would have been heavily negotiated and included in the original pas deal . Moreover, the deal would have specified exactly when the buyout right could be exercised.
F74265A, you may well be right, though based on my experience with such agreements (admittedly, mostly in the realm of investment partnerships in commercial office buildings), "fair market value" would be the price to go by - which sort of precludes anything formulaic. Whatever the case may be, I have a feeling that we haven't heard the last of NS and buying the balance of PAS. I think they may just be playing the game on a bit longer scale than may be apparent at the moment.
Separately: I do most of my railfanning (on the very rare occasions when I am able to find the time) at Shenandoah Jct., not so far from your stomping grounds. I'd look forward to running into you there at some point - you are clearly very knowledgeable about railroads in New England.