A CNC machine is used to drill out the holes, and I'm unsure of the exact type of paint they used (curious, davideak, if you have a reason for asking).
I'm a mechanical engineer so I'm familiar with manufacturing processes,
If this is done by CNC then the pricing would be high due to:
* engineering time to program each individual QR code from 2D to 3D
* set up time for the machine (as its probably not a dedicated one)
* Machine work time (would probably require a small diameter milling head & a longer time to cut due to the slow speed so the tool won't break)
(and this does not take into account the painting - although I would assume the QR area would be pre-painted with the
BTC sign in the front and the CNC process would take care of the contrast after cutting the base of the key-chain, requiring only cleaning after the CNC process is complete)
All in all - this does not seem as a cheap process could easily cost as much as 50$ a piece (in contrast to the generic keychain which probably had the high initial cost of the mold)
Another thought:
I was looking at some new 3D desktop printers (
Example) for my workplace,
With one of these you would be able to low cost print these keychains from a durable ABS plastic.
The machine can have up to 2 different colors - so the QR code can be printed in a different color than the base & give a readable cheap Key chain that would easily be sold for around 15$ - they might not last as much as the metal ones or have a good a finish but they would do the job (I would buy one anyway).
Anyway - I'm keeping my eyes open on this post - hope you are able to produce these in a reasonable consumer price.