Australian Collectors

[Yksrep]

This will be the first time I have ever tried to collect autographs so please understand I'm still a newbie.

I need help in understanding how to do a prepaid reply envelope up in case I get luck and receive an autograph.

As far as I know Australia post offers International reply coupon's for mail, but I don't understand what I have to do with them but that's not my main worry. As stated on the Australia post website

The recipient can redeem the coupon at a post office in the destination country. It can be redeemed for stamps to the value of sending a small letter up to 50g by air mail to any country in the world.

It says up to 50g but what if the weight of the mail being returned is over 50grams, is there any other way (apart from sending money/check which in it's self is not a smart idea) that a prepaid reply envelope be prepared

So if anyone has been in this situation or has any suggestions for me I would really appreciate your advice

Thanks
Daniel