I'd argue the price of Nintendo shit is almost entirely the "Disney of vidya" effect.
My other guess on why PS1/2 & Xbox is cheaper would be how much easier it is to pirate games on real hardware for the others:
- PS1 can use tonyhax to run CD-Rs without a modchip, along with the swap-trick.
- PS2 Has FreeMcBoot with either DVD-Rs or ISOs off a local file server.
- Xbox can be softmodded into booting DVD-Rs or straight from the internal hard drive (this one had the biggest drop in price, IMO.)
In comparison, the GC either requires a custom game save, action replay, or modchip, along with special DVD-Rs
The N64 and Saturn have poor emulation due to special hardware, so the best (and sometimes only) way is to buy the real thing.
Neither have a cheap way to run ROMs either.