Maybe that's a measure of the self-fulfilling dollar incentive toward "renting" someone else's RAM in the future rather than trying to actually own such an outlandishly luxury item :\
I bought whole Intel N100 mini pc with 16GB of DDR5 in it in 2023 for $AUD289 (so about $US200). I got a 16GB (DDR4) SODIMM in 2022 for $AUD88 ($US60).
I was just using that as an example of constant on going price rises, it was the most mundane and not particularly fast ddr5 6000 stuff. The 6400 is even more ridiculous.
Ideally this engineer's approach will yield better performance on lesser equipment in the future, if they keep up the good work after they get more-capable gear to experiment with as time goes by :)
You can, right now, buy a brand new Mini-PC at or above this spec for $600 at retail [1]
Of course, if you want it in a desktop format with a much faster CPU, its going to cost you more.
[1]: https://www.amazon.com/GMKtec-M6-Ultra-Upgraded-Computers/dp...