Since this is about financing, it's hard to say what the numbers until 2020 mean -- it could include deferred depreciation charges and interests.

For the most current cost estimates, see the 2010 report on German Unity projects (pdf!), where the total project costs are estimated at 5.2+2.75 billion, and the money still to spend at the end of 2009 is put at 4+1.4 billion.

Note that the 2.7 billion total for the Ebensfeld-Erfurt high-speed line itself in your link is line with the cost named in this parliamentary reply. The rest of the cost estimate includes the €0.3 billion Nürnberg-Fürth upgrade, some other works and planning, and the one part still without a financing agreement, the four-tracking and upgrading of the Fürth-Bamberg-Ebensfeld section (the 2017 finishing date is only for the Ebensfeld-Erfurt high-speed line). (The 1.95 billion total for Erfurt-Gröbers is also okay if we consider that the rest includes Leipzig-Gröbers, already in operation.) So I'd estimate that the money still to be spent on Ebensfeld-Erfurt alone is about 2 billion.

Methinks a further long delay of the Fürth-Ebensfeld section is more likely than not paying already contracted superstructure and track contractors to the extent that they stop work, or a halt in contracting trackwork; so methinks any further delay will be only a year or two.

_{*Lunatic*, n.
One whose delusions are out of fashion.}