Here's one counterpoint to the "Acela prices never fall close-in" (or might have been a pricing error on Amtrak's part) — had to do a last-minute BOS-NYC trip last month, booked a week out and the Tuesday 7pm NYP-BBY departure was coming in at $220ish, train was showing ~50% full. Booked my ticket (flights were all $350+), but on a whim checked again the day before departure and the same trip was now $58 (train still 50% full, and the 8pm was also ), so cancelled, refunded and rebooked. Feel like this won't happen on a 90% full train, but probably doesn't hurt to check if prices have fallen very close in