VIC tourist attractions: Discount coupns (Phillip Island, Otway Fly)

Could someone advice me where to find discount coupons to the following attractions in VIC?

1. Otway Fly
2. Phillip Island (3 park pass)

I know that MyNRMA website offers 7.5% off (they advertise as 10% off, but charge a 2.5% credit card fee bring the real discount down to 7.5%)