I went ahead and bought my 6am Richmond to BWI ticket because there were only three seats left at the cheap price (what the hell, that is 55 days away, who is booking all those seats?) and when I checked if going to the other station would be better those tickets were twice as much. I don't begin to understand any of that.
And I will probably get a chance to hang out in the Metropolitan Lounge in DC waiting for that 10pm departure. I was hoping I'd be able to visit one of those somewhere. Whee!