I wonder where this requirement comes from ...
None of the Arctic Cooling fans I had ever failed or lost performance over the years. Even their first generation desktop fan (Breeze) which runs multiple 8-12 hour shifts with me for the last decade shows any age.
If anyone knows of any, let me know!
Q64-22 on eBay (US) for $150-200 USD / 542-723 PLN.
https://www.ebay.com/itm/365380821650
https://www.ebay.com/itm/365572689742