3,500 mi x 8 million/mi ~ 28,000 million, 也就是$280億
數量多有規模效應，100英裏就能便宜10%。所以是這個數量級，當然海底的地質困難也許會是個變數。
下麵是boring company對普通隧道的估價：
Playing around with it, for a bare tunnel it looks like $1.1 million USD to show up*, and $5.5-$8 million USD per mile of tunnel. Tunnel cost drops by approx 5% for 10 miles, 10% for 100 miles.
