This chip exists entirely as a file on a computer, and maybe a few FPGAs, so I doubt even the company announcing this has very much idea. It seems as if they're hoping to get SMIC to manufacture this, so it won't exactly be a competitive node (although China is pouring vast amounts of resources into making their semiconductor manufacturing competitive, so give it a few years).

So far is this thing actually from being produced? (In time and cost)

Although it sounds radical (16 cores!) it's a rather low end chip. So months to a year, and millions to low 10s of millions of dollars. However the Chinese govt is massively investing in semiconductors at the moment so they will regard that as valuable research and investment rather than a cost.

A better question would be, how does it compare to ARM?

ARM is generally more competitive in terms of price and power, less competitive in peak performance.

RISC-V would have the added price advantage of being royalty-free.