Simplest explanation of how the master set (1982-2017 1oz, 1/2, 1/4, 1/10, 1/20, one of each coin from each date, varieties don't matter, coins at least ms68 quality) process plays out is:
1) Bank chooses several prominent mainland dealers to make certain number of sets with a fixed offer price
2) These dealers source coins from their own inventory, marketplace, online auctions and US/Germany dealers
3) Dealers sells the completed set to the bank in capsules and bank puts the coins in presentation case
4) Bank sells the completed set to their customers or customers buy the set to gift to someone - owners of the sets are investors, not collectors.
The only variable is how many sets the bank orders in a given month. If the number of sets ordered exceeds the inventory of coins available in the marketplace, prices rise for coins dealers are missing, because dealers are required to deliver the sets in order to protect their reputation.
There are other set configurations beside the complete master set, such as a complete 1/10 series set, complete 1oz silver panda set, etc., some of these other sets are promoted not only in China but in Europe and US (telemarketing).
Nobody knows the end game, however, only 1000-2000 sets are possible so once they are all made then other configurations will become popular, trying to predict what those will be the challenge for the next 5-20 years.
There are two ways to make money, one is build your own master set and sell it to one of these dealers, second is buy up the coins that you think are difficult to find, buy them up and put them away until the price spikes on them.
The more supply each of us takes off the market the faster prices will rise. For now 1/2oz and 1/4oz are what limits how many master sets can be made. There will come a day when other set configuration are made, say 1oz series set, then certain 1oz coins will limit how many sets can be made.
Choose who you sell your coins to carefully if are still invested in the market after you sell, ideal buyer is one that will put the coins away for a long time, rather than flip for quick profit. I sell 85% of the 1oz, 1/10oz and 1/20oz, 65% of the 1/4oz and only 20% of the 1/2oz I receive in a given year.
Finally, once the market matures and supply is non-existent, then collector coins will become hot, 69s and 70s, varieties, errors, proof sets, etc. I am holding my collection for this day, that is why I sell all ms68 coins to the master set builders.