broker/makler fees in Berlin are usually paid by the owner as far as I have found. this may change now that demand is so much higher than supply. it certainly wasn't like this 5 years ago.
Yes, Berlin still has (or at least recently had) an oversupply of living space. Look at Hamburg or Munich, and you'll see that nearly every listed apartment has the broker's fee of 2.38 monthly rents (legal maximum) payable by the tenant.