Hi @Judi9877 I found a proof set of coins from your year of birth on this website.

https://melbournecoinshop.com.au/product/1977-proof-set/ 

At a quick glance this shop was the cheapest at $60 for this set. This is the best quality of coin you can get. Your lucky, depending on how many coins were minted in your year of birth, it dictates how expensive the sets will be. And by that price I would say there was a fair amount of coins minted. My year of birth must have been not as many, as the price for my year is around $175. But it definitely pays to research and look around for the best price.  I have created a spreadsheet that I use, with about 50 different coin shops on the Web. And I will search each site for a particular coins⁰, and see who is the cheapest including postage. 

I wasn't going to collect coins from other countries, but some were so beautiful that I couldn't resist. 

This one is my favourite 

And since I was born on the date man first walked on the moon, I couldn't go past this coin. I haven't received it yet, but it should arrive any day now.

If you want to buy new coins when they are released, businesses and the Royal Australian Mint have set up a ballot system now, that you enter into, and then you will get an email if you have won the right to purchase that coin or not. My first one was unsuccessful, but have managed to win the others I have entered into.

This is supposed to stop people buying a heap to sell for ridiculous prices. Most shops these days will apply a limit on how many new release coins can be purchased, to try and help the actual collectors obtain these coins, instead of the greedy people that are only in it to make money.