For more context, sample reference materials from the NIST reference catalogue are not meant to be exceptionally high purity examples of the sample -- SRMs are usually commercially-produced products. The real value is that each sample comes with a datasheet with incredibly detailed and accurate measurements that are (as you said) used for calibration of measuring devices in industrial settings. To quote a Veritasium video about the topic from a few years ago[1], "the thing you're paying for is not the peanut butter, it's the knowledge of exactly what is in the peanut butter".

[1]: https://youtu.be/esQyYGezS7c?t=226

SRM 2387 pairs well with a cup of ISO 3103.

https://en.wikipedia.org/wiki/ISO_3103

Yes, it’s a bit frightening to know what a hidden dependency NIST is on many things. In my industry, all calibrations ultimately derive from physical NIST standards for resistance, frequency, etc.

You can still make cookies out of reference and/or lab materials :)

https://www.youtube.com/watch?v=crjxpZHv7Hk

I wouldn’t put it past people in my country to buy it just to show off wealth :/

I have recently realized we imported the western world in the most superficial ways.