Hello Victor,
two cases:
(1) If you go to Berlin and
do not know anybody living there:
Ask for stores in
DigitalFotoNetz.de :: Index (german
forum specialized in Pentax) (english should be possible).
Alternatively go to:
Pentax (Samsung) - DSLR-Forum (general DSLR forum, link is the Pentax section)
(2) If you go to Berlin and
know somebody living there:
Better
buy online. This is cheaper and you have the
legal right to return it without reason within 2 weeks after receipt and getting the money back.
Good Price searching machines are:
Preisvergleich Geizhals.at Deutschland or
PreisSuchmaschine.de - Ihr Preisvergleich - Deutschland or
guenstiger.de - Der grosse Preisvergleich im Internet
It is extremely recommendable to
look not only at the price, but the
availability of the lens and
reputation of the dealer (I usually do not buy the cheapest one, for reputation reasons).
Best regards
Jacob