I ran into a new NPC and asked them the standard 'what's the chatter', and without any sort of prompt I was told it would cost me 500c and that I handed over 500c. This is not a significant sum of chyen, but I am irritated that my character was forced by the game to pay for something that I would not have consented to had I been given a prompt.
I believe any time you're paying for something, you should be given the option to pay or to decline and abort the transaction.