you all have kind of wandered away for the original point of "why is it taking so long?" and what I said originally is that...
1. It's a very complex structure. Meaning that every single little piece is a custom made piece, and they all have to go together one at time
2. It's being done in a small confined area. There is only so much equipment and crew that they can fit into that area at a given time to do that complex work, and the reason it's being done in a small confided area is to keep the rest of New Fantasyland open. This is the real trade off, in order to keep the rest of New Fantasyland open you have to work in this small confided area
3. It's surrounded by the guests. Keeping the rest of the area open means it surrounded by people on all sides, which creates a safety concern for the public, which in turn forces them to work in a small confined area, which limits the amount of equipment and crew they can use, to build the very complex structure one piece at a time, and this is the reason "why it is taking so long"
And the reason they are paying for it in the 2nd Quarter of next year is because this is when they estimate Mine Train will finally be finished. It could come in under schedule/budget or it could come in over schedule/budget, but they won't know exactly how much it will cost to build, until it's FINISHED BEING BUILT!
It's like going to a grocery store, you spend "X" amount of time filling you're cart with stuff, but you won't know how much all the stuff in your cart is going to cost until the end, when ring up the cost of all the individual stuff
...ya get it yet?