"Sharing between users" doesn't make it cheaper. It makes it more expensive due to the inherent inefficiencies of switching user contexts. (Unless your sales people are doing some underhanded market segmentation trickery, of course.)
No, batched inference can work very well. Depending on architecture, you can get 100x or even more tokens out of the system if you feed it multiple requests in parallel.
Of course that doesn't map well to an individual chatting with a chat bot. It does map well to something like "hey, laptop, summarize these 10,000 documents."
