Garona-B-V-Azure-Leopard When you need a occupational insurance (beroepsaansprakelijkheidsverzekering) it's always better to shop around for the best policies and prices.
You could try to ask an trade organisation like MKB Nederland or a branch specific organisation. Or visit a insurance broker (verzekeringsadviseur) for more advise.
A bank that asks you to tale other services together with the insurance is never a good sign, as most banks don't do insurances themselves. ING has Nationale Nederlanden, Rabobank has Interpolis, Knab has Aegon (as Knab is a subsidiary of Aegon) and so fort. Try to contact those companies direct and not via am intermediate bank.