An example of your money spent for 6 ropes, 6mm: cost 1248 CZK, with shipping to Germany and tax and customs duty (+50% to price) you pay 2672 CZK, which is 102,8 Euro instead of 48 Euro for 6 ropes... For my comparison Esinem's tossa rope should cost you 129-184 Euro (may not be actual price), 78 Euro for normal jute ropes (Shipping from England should be cheeper, but still high). The real diameter of the ropes should be 5mm because Esinem declares nominal value 6mm is 5mm at real.
I think that even that I have low price, I am not well known in the world of rope selling hence no-one would buy from me because all of these factors.
This is set of ropes 3-ply twisted jute 6mm, 8m length; 4 ply rope is for suspension line (red endings). Braided ropes 4x8 or 4x6 mm are above.
3-ply 6mm ropes have minimum diameter just after dried: 5.4-5.5mm, after been oiled and used they have 6 mm.
4-ply 7-8mm nominal, minimum diameter was 6mm just after dried, after been oiled and used it has 7-8mm.
I can prepare rope for shibari from 4-ply natural ropes with 6mm diameter which I can buy from distributor. The distributor promises load bearing capacity 300 kg for single line, but because the price is higher, so the total price could be same or even higher.