That "expansion pak" RDRAM upgrade was designed to give the N64DD enough buffer space so devs could continue using about 4MB of RAM for everything else, so I can't imagine how expensive the N64 would have been if they had to ship it with 8MB of RDRAM to maintain the same standard of visual quality and a 2X CD-ROM drive.

Then again, the good games would have been $50 instead of $70, and there would have been a lot more developers willing to pay $0.20 per unit to ship games than $20 per unit for the common 12MB and 16MB ROM chips.

However, I don't know if Ocarina of Time or Majora's Mask would have worked as well without that ability to load entire scenes in < 500ms. Diddy Kong Racing and Indiana Jones & The Infernal Machine relied on the ability to stream data from the cartridge in real time to smoothly transition between scenes/areas. DKR only used it in the overworld AFAIK, but it was still impressive.

Not saying you're wrong, just that I'm glad things turned out the way they did because Ocarina and Majora's Mask likely could not have been done on a Saturn or PS1 beefed up with the N64's GPU.

I could be wrong, and some experienced romhackers could conjure up enough clever optimizations to make a faithful PS1 port of Ocarina of Time that doesn't have noticeable load times, but it would have been the result of years of research with no deadline pressure. I admit I'm just speculating, but not in a presumptuous and baseless way.

There was actually an unauthorized third-party CD-ROM drive for it, the Bung Doctor V64[1]. It didn't actually expand the available ROM space beyond what was possible with cartidges, but its still interesting in that it was allegedly used by licensed Nintendo devs as a lower-cost alternative to the devkits officially provided to them.

[1] https://en.wikipedia.org/wiki/Doctor_V64

And a bit more texture memory!