ridiculously inexpensive flights can be had by http://www.ryanair.com/en but they fly out of the smaller airports which can be a pain to get to/out of :-/

when I was stationed in Germany, I flew from Frankfurt to Pisa Italy round-trip for 40euro (about $55)

http://www.italiarail.com/ is good for Italy rail travel & http://www.bahn.de/i/view/USA/en/index.shtml if you find yourself in Germany