It is expensive. They charge in 6 second increments. I have not found anywhere that says how much per 6 second stream.
Okay found it, $0.24 per minute, on the bottom of the pricing page.
That means they can spend $14/hour on GPU and still break even. So I believe that leaves a bit of room for profit.
Scroll down the page and the per minute pricing is there: https://www.tavus.io/pricing
We bill in 6 second increments, so you only pay for what you use in 6 second bins.