Acid Jazz's story reminds me of a Patricio, guy from Uruguay whom I met some ten years ago. He was traveling through my country and got to the train station. I was waiting for my girlfriend and noticed a boy who were hustled by cab drivers. He was almost "cooked" and some of cab drivers would take him in "nice hotel" (cheap hostel) for a very low price (probably all money he had with him). We took him with us and he stayed for a week. We dispatched him for Macedonia and Greece (but firstly briefed him where to go and how to behave). He is still the adventurer, we are in the contact through the facebook now.
Anyway, if someone wants to travel to eastern Europe like that I strongly suggest DON'T!
Living standard is lower then in western Europe so there is no food in the dumpsters, people don't have money, so you would earn nothing by "busking". There is no "squats" so you will not have where to stay.
And the biggest danger are the Gypsies (so called "Roma people"). Forget anything that you maybe heard of them or seen in the movies. They are NOT happy and free street singers dissociated and misunderstood from evil society. They are baggers, thieves and robbers (and thats the better part of them). If you get in contact with them, and most probably you would by traveling like that, because they are "the kings" of the streets, you can end up robed and most probably dead.