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Man-in-the-Middle PCB Unlocks HP Ink Cartridges
(hackaday.com)
This is a most excellent place for technology news and articles.
for bonus points get a used one!
If you're extra lucky, it'll still be running on the original included demo toner cartridge.
I have a brother multifuction laser. From a thrift store. 6 years so far on a 3rd party XL toner...
I've spent more on paper than the printer+toner
Bonus bonus points: get a free new one!