Bayern are favourites but Dortmund have a good team, you certainly cant write them off. I prefer Dortmund to Bayern, I like their model of buying young players & developing them.
It was only their way to make a profit by buying young players at a low price and after the player had the price, Dortmund would sell it. it's exactly the same as the Ajax method. But Ajax prefers not to buy players. Because they usually foster their Academy to become a professional player.
But it must be remembered, in 3 matches played Dortmund. They haven't won at all and all the matches ended in a draw.