The Intel 4004 is a 4-bit central processing unit (CPU) released by Intel Corporation in 1971. Sold for US$60 (equivalent to $450 in 2023), it was the first commercially produced microprocessor, and the first in a long line of Intel CPUs.
https://github.com/davepinch/pinchy.cc/blob/master/content/topics/computers/microprocessors/intel-4004/en.wikipedia.org.md