If you spent a ton of money to hike across Europe, you've done something terribly wrong. I spent a month traveling across Europe by train a few years ago, and it was fairly cheap, certainly FAR less money than I would have spent on any vacation in the US.

Taking a vacation (any vacation) in the US is a frivolity, even if you live in the US. If you could theoretically rent out your home in the US while you're gone (for the same cost as your current rent+utilities, so no net profit), you'd probably end up saving money by spending a 2+ week vacation in Europe instead of just spending that time at home and going out to restaurants in your own town.