To and From Eastern Europe from Western Europe

[brentd49]

Any ideas on how to travel between Eastern and Western Europe, i.e., this is a section of my itinery:

Rome-Athens $164 (plane) --not bad

Athens-Budapest $367 (plane) --too much money (I couldn't figure out how much train travel would be.. I think I have to split it up city to city, recommendations?)

Budapest-Prague $96 (train) --not bad

Prague-(Frankfurt)-Amsterdam $245 (train) --a little much (I belive the plane was twice expensive)

So my bigest complaint is Athens to Budapest, that just seems like too much money to be traveling in Eastern Europe. I'm considering leaving Athens out of the itinery because it's my biggest travel expense right now, but I really want to go. So please offer me some wisdom sages. Thanks.