Berlin is served by the ports of Warnemunde and Rostock, but is not actually a cruise port. Combined, Warnemunde and Rostock serves as the departure port for only five cruises yearly from MSC to Europe.
On average Berlin is rather affordable compared to other ports. Cruises leaving from Berlin during the peak seasons of spring and summer are considerably more expensive than the the low season of fall. Look at the diagram below for the monthly average cost per day (Cruises only depart from Berlin between May and September).