This was kind of covered in the article. The 68000 is a weird chimera. It had 8 32 bit data registers and 7 32-bit address registers. This was to be compatible with a future 32bit world. The bus to the outside was 16-bit due to the cost of ram and the compatibility with peripherals. Remember. This was on the drawing board 76-79 before release and production before advances that drove later versions to be fully 32-bit. Same for the address space. 16-bit machines could address 64k. With 24 bits you could address space you could have a max of 16mb which was a ridiculous , near limitless amount of ram for the period. The great thing about the 68k and this 24 bit adress space was that it was a large linear address space. You didn’t have to work in 64k segments like the Intel world.

The 1MB Lisa cost U$ 10,000 and the Mac at 128k was u$2500. A large chunk of that cost was the CPU and RAM.

https://en.wikipedia.org/wiki/Motorola_68000