I drove around Europe in a $500 beater, and Finland was too expensive to stay in for me at the time, but by far the most impressionable thing to me about the people was their penchant to take fashion to the extreme. If you're a jock type, you've got the sneakers, jersey, headband, wristbands, lol. If you're gothic, you've got facial piercings, powdered white face, chains everywhere. Etcetera. I've never seen anything quite like that before, not even close.
Of course, I'd only go in the summer. That's the most north I've ever been, and the Baltic does freeze at the coastline.
I highly recommend taking the super large ferry to Stockholm.
It was very affordable, and this moving island that they call a boat had a casino, two story dance hall, 4 aisle grocery store, bowling alley, at least 6 large glass elevators, lol. Of course, it was cheap to me, because I was sleeping below the water line. It's an overnight trip, and I barely slept.