Okay, so after another round of emails today I have more infos. I can purchase white pergamenata, 230g/m² at 70x100cm from Fischer CH. The price works out to 3,00€ with tax ( swiss tax) but without shipping costs per sheet of paper.
The price I was given in germany for the same size paper was 5, euros per sheet (70x100cm) and this was 4 years ago.
I can purchase naturale Pergamenata at the same price but with a wait time of c. two weeks. I must make a minimum order of 200, CHF or above for these prices. ( I need to absolutely order a min of 60 sheets to make this work to our advantage.)
1 sheet of 70x100 will give you 4 scrolls at A4 size.
This is an excellent price for this paper.