I booked my cheapest one-month trip
Ha, that reminds me of the time when we found a loophole in the European train ticket price system: Deutsche Bahn had (and still has I think) a "Europe Special" where you could buy a ticket from any town in Germany to any town in Europe for 39 EUR flat. Our idea was to travel through Croatia for a few weeks, and we wanted to book a train ticket to Zagreb, from where we would start our trip. Sure enough, bahn.de (the journey planer of Deutsche Bahn) offered us a ticket for a train ride of around 16 hours from our home town to Zagreb, through Austria and Slovenia. We would have had to change trains 2 times.Then things escalated.We discovered that we could book the same trip, for the same price, but with a different route, making a 500 km detour inside Germany over my parent's town. Then we discovered that bahn.de allowed us to specify a minimum time to change trains. We set it to 24 hours at my parent's town, letting us stay at my parents for a night. Then we found out that we could set an additional via option in such a way that we had to change trains in Ljubljana. We set the minimum time to change trains there to 24 hours. Then we found out that the ticket price was the same if we travelled not only to Zagreb, but to Split (at the coast), which required a change of trains in Zagreb. But we wanted to stay a few days in Zagreb, and the maximum minimum time to change trains on bahn.de was 24 hours. We then discovered that (at least 5 years ago) all foreign tickets were valid for 30 days in Croatia. Effectively, this meant that we could stay in Zagreb for 30 days, and our ticket to Split was still valid.We got the ticket. After a week of visiting my parents (1 night stay), Ljubljana (1 night stay), and Zagreb (5 nights stay), we arrived in Split without problems. It was a 1,500 km, 7 day train trip for 39 EUR.The only minor problem we had was the German conductor in the first train after we visited my parents. He just stared at the monstrous ticket in disbelief and had to finally conclude that it was valid.After 10 days at the Dalmatian coast, we took the bus home.