IEEE's MAC address allocations have a weird pricing structure.
If you want to buy a 12 (aka 4096 addresses), that's $855 one time [standards.ieee.org] (or $0.20 per MAC address).
However you can buy 20 bits of space (1Mil addresses) for $2,030 one time [standards.ieee.org] !, and 24 bits (16Mil) for $3,375 one time [standards.ieee.org] !
I somewhat question the desire to buy 4096 MAC addresses when 1 million is only around 2x the price.
Side note, I love the idea that you can just "buy" MAC addresses in a physical form. Because microchip sell EEPROMs with guaranteed to be unique MAC addresses [www.microchip.com] from their own pool.
1 EEPROM with a MAC uniq address burned into it costs about £0.20 [www.mouser.co.uk]
@benjojo 1KiB EEPROM for 64 bits seems a little excessive
@q [glauca.space] it also comes with a 128 bit ID as well, some of them you can write some bits yourself too. It sort of makes sense for small scale products, but it's a bit of a weird SKU in general