Yea, for people who don't really understand what Jack Tramiel/Commodore did specifically:
Commodore bought the MOS company. The company that developed the 6502 CPU used in many 8-bit computers at the time, and also built all the chips for the Commodore computers.
Because they were now controlling the entire chip production, Commodore could massively cut manufacturing costs on their entire lineup.
The result was that the C64 was priced exceptionally low, especially considering that it had 64k of memory, which was 'a lot', back in those days.
This made the C64 affordable for many people, resulting in a big home computing boom.
The Amiga (and also Atari ST) continued the trend of offering a lot of value for money.
I recall that you could buy an Amiga 500 (or Atari ST) for less than half the price of an XT-class PC.
Which is especially impressive considering that the Amiga 500 was a far more powerful computer (much better audio and video, a faster 16-bit 68000 CPU , and a multitasking OS with a GUI, compared to Hercules/CGA, PC speaker, an 8-bit 8088 CPU and DOS).
And then there's the extra cost saver that you didn't need a dedicated monitor (which people did not have back then). You could connect these home computers to any TV set. That hasn't been a common option on PCs until recently, when s-video output became standard on many videocards, and now because HDMI and DVI are mostly compatible.
Even today, computers are not that much cheaper than the C64/Amiga/Atari ST were back in the day. And they're still generally larger and more cumbersome than the cleanly designed home computers of that era, with the keyboard doubling as the system case, instead of a separate clunky and noisy box on the desktop or floor.