We calculate postage as a lump sum per shipment. The number of books is immaterial; what counts is the place of delivery.
Shipping costs for deliveries within Germany:
up to 0.45 kg: 1.45 EUR
up to 0.90 kg: 2.60 EUR
up to 1.8 kg: 4.50 EUR
up to 9,00 kg: 9,00 EUR
up to 29,00 kg: 15,00 EUR
Shipping costs for deliveries outside of Germany: