Arguably the MOS 6502 processor was really no better than Motorola 6800 that was its direct predecessor, and why would you buy the most important part of your computer from a calculator chip company like MOS Technologies instead of a more stable company like Motorola?
The answer is clear. $25 The 6502 was merely 1/6th the cost of a Motorola 6800.
Think about it. Without this low price, Steve Wozniak would not have produced the Apple I and Apple II computers as we know them, and Commodore could not have produced the PET, VIC-20, C64, etc. The Atari VCS and Nintendo NES would never have existed.
The home computer market would have evolved more slowly and in a completely different direction.