Boston is almost 3 times as far from NY as Beijing is from Tianjin. Trenton, on the other hand, can be gotten to in under an hour and for $40. I just did a quick search and found that the Beijing-Tianjin fare is actually about $15, not $6.
So it does seem on paper that China has Amtrak beat by an economic factor of 2-3x, but this is also before you factor in local purchasing parity and so on.