[SampleMan]

If that tunnel could be built for $12 billion I’ll eat my hat. A billion dollars just doesn’t go as far as it used to. What was the price tag on the big dig again?

[ThePythonicCow]

The Big Dig was in an urban environment, with complexities galore. It had a total length of 161 lane miles (number of lanes times number of miles.)

This Bering Strait tunnel is basically a straight shot, with no existing impediments, for a total length of 64 miles. If it's two lanes (one track each way) then that's fewer lane miles than the Big Dig.

And, as corrupt as Russia is, it might still be less corrupt than Boston.