We will be in Sydney 8/18-8/24, and again from 9/13-9/16. I've found a price of $375 for two for harbor bridge climb. Seems a good price compared to what I've read. Still, when I go to sign up, I'm asked if I have a discount code or coupon. I don't. Are such things available for this? If so, are they available on line, or only from locations in Sydney? Thanks.