Where to find the cheapest EEPROM with pre-programmed unique ID?

The cheapest I²C EEPROM I found which has a pre-programmed unique ID is the HANSCHIP semiconductor AT24C02CDBVRG which - according to the datasheet - has a 128-bit pre-programmed unique ID and is available in a SOT-23-5 package.

It’s currently available for 0.0325€/pc @ 100pcs at LCSC (as of 2024-09-08) and appears to be an Atmel (now Microchip) AT24C02C clone - therefore, it is most likely compatible with its pinout.

While it doesnt’t have a ton of memory (only 2 kbits), it’s a great choice for applications where you need a unique ID and don’t want to deal with programming it yourself.

So far, I have not used it in production, but I will update this post when I have.