No idea. I just know it will mostly be bus/train travel, or HH if you have experience (I dont). Sleeping in Hostels, CouchSurfing, Campsites, or the kindness of strangers. Id like to do something crazy every once in a while: white water rafting, canyoning, mountain biking, sailing, ...whatever wont cost an arm-and-a-leg... but its August. Could be booked.
Explore Eastern Europe. Overland. Budapest to Athens.
Still looking for flights? You can have flight experts compete against one another to find you the absolute best and cheapest flights.