Unfortunately a bit of hooliganism creeping back in. Couple of hundred Dresden "casuals" created havoc after running at the gates and stewards at the cup game with Hanover on Wednesday night (since reunification there has been a bit of needle between H96 & Dresden). Added to that there was a fair bit of aggro at the recent Dortmund ~ Schalke game! Hopefully gets nipped in the bud!
Due to the fan numbers, then the free public transport makes sense. Much better to have everyone on trams, buses or local trains than clogging up the streets with their own cars. Plus the amount of extra public transport put on at the end of the game negates the need for a "subway loyal" type scenario.
As mentioned above, standing areas are cheap & cheerful. My season ticket at Hanover 96 (terracing behind goals) works out at 10 €uro per game.
Away tickets (standing) are also good value (was at Frankfurt 2 weeks ago, cost = 15 €uro). Getting standing tickets in the BL1 can be difficult for away games, most get allocated to the supporters clubs. Away tickets for the seated sections can be v. expensive (for what is either a seat behind the goals or in the corner). Last year was at Dortmund 46 €uro, Munich 49,50 €uro, Wolfsburg 19 €uro, Berlin 37 €uro.