Now they've added gold proofs. Thank goodness they can't go back to 2017 and 2018 and add proofs to those years. I'm done with the series. These mints know how to milk a series for all it is worth, sadly. https://www.apmex.com/category/16701/perth-mint-gold-swan-coins
There really isn’t a way to tell how long a series continues with the Perth, because as long as there is money to be made, it will continue. Initially this was only supposed to be a 3 piece set, but of course the greed sets in, and now they will continue, from what I understand...will it be 3, or 5 or 30? Who knows. But as long as people continue to suck them up, they will continue to make them, IMHO.