I wouldn't say that. 2GB dev kit is $50 depending on where you buy them. That's much more bang for the buck, even if you opt out using the tensor cores they were designed for.
A board with a m2 port costs an extra $300 and only exists since last year: https://antmicro.com/blog/2020/04/updated-jetson-nano-xavier...
It should have been standard and by default from the beginning.
They can also boot from USB3 as of recently, which boosts storage access speed tremendously.