I have taken Amtrak often for the last several years. I usually buy my tickets for myself and a g/f several months ahead of time. I noticed today I bought a bedroom on the Southwest Chieft to Los Angeles it would be around 600 or so dollars....much cheaper than I would pay for a trip in September to the same city. Should I wait to buy a ticket closer to my departure date or is that too much of a risk on not getting the departure date I want at a good price???