Just think - we could do three or four megaprojects a year with a 2006-esque budget elsewhere plus those kinds of budget deficits.
Of course, as anyone in California is painfully aware, the high-speed rail project is a complete joke :) you'd need to trust that this one would do better.
Also, as an economics aside: In the private sector, a $280 billion project should hope to earn in the neighborhood of $11 billion a year in profit/savings in order to cover the cost of capital. This is, of course, after equipment maintenance, fuel/power, deprecation, labor, etc.
It begs of a cost-study, I mean, I'd gladly pay 4x the current cost of an economy flight from NYC->London if I could take a train of equal comfort that only took an hour or two.
Which is roughly 1 / 14th the cost of the Iraq war. Not bad if you think about it.