Our Notary provided a translator and also sent the contract out ahead of time in English so we could properly review it with the bank (first time buying in Switzerland) Our sellers were doing it alone though so no confusing agents to deal with. The cost of the translator was negligible and certainly not 1000chf. The notar spoke better English than the translator but has to be impartial. The translator basically read us the English copy we had in front of us. The bank had already confirmed that both copies were the same etc etc. It really doesn't have to be so complicated. Maybe you could ask the bank to speak to the Notar and see what they advice (I am sure they have a list and can have it trabslated pre signing)

hth and good luck (it is scarily easy in the end)

Caz