The Intel line was fathered by the Datapoint 2200; they implemented the CPU in TTL logic boards.

https://en.m.wikipedia.org/wiki/Datapoint_2200

The 6502 line came out Motorola's failure to "indulge" their employees in a low-cost 6800, thus unintentionally fathering MOS Technologies.

https://en.m.wikipedia.org/wiki/MOS_Technology_6502

The 6502 was extremely inexpensive. The first implementation was the KIM-1, so this is the first on that side.

https://en.m.wikipedia.org/wiki/KIM-1