I actually bought some when I was in Austria 12 months ago. The shop I was in builds guns and gets Eley to produce paper case cartridges for them. I paid from memory 8euro per 10.When i lived in the Midlands, I bought paper cased 12 bore cartridges from William Powell, their own branded case. Excellent. I still have a full box.
I now use a twenty bore, and have shot Three Crowns for years, another nice shooting cartridge. I also tried Rottweil Waidmannsheil in paper, but I do not think that they are still available.