It is equally convenient for me to start a MR from any of the WAS airports (IAD, DCA, or BWI), since none are more than 40 minutes from my door. PHL is not a geographically desirable starting point, but when the deal is right, I am willing to consider it. (Purchased tickets to FCO starting in PHL when the Priceline opportunity was there in February, but had to cancel at the last minute on account of illness in the family.) Now there is the ANC sale, which ends tonight, and it is considerably cheaper to start from PHL than WAS, about $160 cheaper. So can anyone help with the following question:

getting to PHL other than by car. Would rather not drive to PHL, if there is a practical alternative. Does Amtrak go to the PHL airport, as it does to BWI? Or can one go to via Amtrak to a PHL station, then make it out to the airport by some cheap, easy and fast means (e.g., a local commuter train)? If I could do it other than by car, then I might be able to arrange the return through IAD and simply skip out on the last segment.