Of all the useless conversations we tend to have around here, this one has to be the most useless. Why do we argue about what the cost might be? Armed with that information are we going to picket the place to have them build more Monorail track or are we going to decide that since Disney is unwilling to spend 100mil per mile, that it is not being done just because they are to cheap to spend massive amounts of money on something that isn't really needed? We have an operating Monorail system that is far more in need of new trains then any added length to the track, which will do nothing about upgrading the trains themselves.
As far as the OP, and believe me it hurts to back him up, what he did was tell us what Vegas is spending, which is fine, but to say that it answers any question other then how much Vegas paid for it, is quite a stretch. Everyone just needs to get over it, if Disney had any intention of expanding it here, now, in 2016 there is no indication that they are even thinking about it, much less getting ready to ask the BoD for the money. No matter when or if, it had been talked about decades ago means absolutely nothing, with or without "hidden" footings.