Does amtrak mean metro/subway ? Sorry, never heard the word before.
For low cost room in a hotel, I'd suggest you look here
, and hostel room here.
I lived for 15 years in Montreal, but of course never had to sleep in a hotel. I can't therefore suggest any particular place. But if some places from the above links appeals to you, tell me and I'd be able to tell if the location is great or not.