Palmolive Sensitive shaving cream
Palmolive Classic shaving cream ( Much cheaper then in the UK )
Wilkinson Sword Shaving cream
Nivea Men Shaving cream
Wilkinson Sword Shaving Stick
Florena Men Shaving cream
Speick Shaving Cream
Speick Aftershave Lotion
Speick Aftershave Balsem if to be found.
All these products that I named cost under € 3 and most less then € 1,30 and only the Speick Aftershave would be around € 8.
Oh Nivea also sells a menthol aftershave balm called Cool Kick and it wouldn't cost more then € 5.
If you use Google translate then you can take a look at mine
German shopping guide which includes prices as well and which stores you could find it.
Although I don't know if it would be same in Berlin, but I have been in many german cities and what the stores sell is mostly the same.
Oh if you could find Kappus shaving cream then I would really recommend you to buy it as its a great shaving cream at the price level of Nivea Men / Palmolive but the luxury is comparable with Speick shaving cream.