Earlier quoted context omitted.
Same here, I've taken the London to Edinburgh on LNER and Virgin East Coast multiple times and it runs about £40 each way. And my 30 mile train into Manhattan is $14 $36 one way for a 5 hour train seems pretty cheap.
The problem is that the train has to compete with 3 hours by car... And then the ability to actually use a car at your destination. The transit systems in either Seattle, or Portland, are nowhere near as good as they are in New York.
You can also rent a car when you get there for something like the same amount for the day and not worry about the wear and tear part.