What type of system is needed to self host this? How much would it cost?

Depends how many users you have and what is "production grade" for you but like 500k gets you a 8x B200 machine.

Depends on fast you want it to be. I’m guessing a couple of $10k mac studio boxes could run it, but probably not fast enough to enjoy using it.

One GB200 NVL72 from Nvidia would do it. $2-3 million, or so. If you're a corporation, say Walmart or PayPal, that's not out of the question.

If you want to go budget corporate, 7 x H200 is just barely going to run it, but all in, $300k ought to do it.

How many users can you serve with that?

For the H200, between 150-700. The GB200 gets you something like 2-10k users.

$20K worth of RTX 6000 Blackwell cards should let you run the Flash version of the model.

But can be, and is, done. I work for a bootstrapped startup that hosts a DeepSeek v3 retrain on our own GPUs. We are highly profitable. We're certainly not the only ones in the space, as I'm personally aware of several other startups hosting their own GLM or DeepSeek models.

Why a retrain? What are you using the model for?