The comments here that GRS gets paid well for running the Downeaster made me do a little research into what they really get... some stats from ATK's website are pretty interesting:
In 2003, ATK paid $96.2 million to "host" railroads for running rights. In April, 2004, they ran 2.159 million train-miles on those roads. That works out to $3.71 per train-mile. GRS owns ~80 track-miles on this route. 80*3.71= $297 each way.
Now, I'm using averages and extrapolations here (and if anyone has more accurate stats, lets see 'em), but those figures are probably directionally accurate... and it ain't a lot of money for the railroad, when you consider the required condition of the track, dispatching, freight delays (put a train in the hole for an hour will cost you ~$100 in labor[including fringe], and a lot more in locomotive costs, freight car per diem, etc).
By way of comparison, GRS makes as much as $1,000/car or more on private car received traffic that moves about the same distance, albeit with their own crews and power.
And everyone wonders why the Class 1s and regionals hate passenger trains!