Going to Mikkeli from Bremerhaven, Germany

The easiest way to go to Finland in general and more specifically going to Mikkeli from Bremerhaven is taking a plane.
Ryanair offers cheap flights from Bremen to Tampere. Depending on the time between booking and flight the price is about 30-40€.
The disadvantage is the limit for baggageweight of 15kg for suitcases, bags or other items and 10kg for hand-baggage.
From Tampere there are two possibilities for reaching Mikkeli. One is to take "north-route" around lakes using the train to Pieksamäki and change there to the train destined for Helsinki, which also stops in Mikkeli. This route takes about 3 hours and costs about 25€ with the finnish student ticket.
The other possibility is to take the "south-route" via Tikkurila to Mikkeli. This route takes a bit more than 4 hours and costs around 20€ with the student ticket.