A friend suggested going by bus to Poznan and from there by train to Krakow.
He said there is no particular reason to go to Poznan, but as whole it's a nice trip. You get to know a bit of Poland and a city that otherwise you would never visit. The price compared to an airplane trip is almost the same. From Poznan to Krakow it's possible to travel at night saving the price of the hotel/hostel.
Time is not an issue.
Is this a good idea? would it be better/cheaper just to fly to Krakow?
Hitchhiking is not an option. Even having time I need to know in advance how much time I will spend travelling.