15 million a piece. I don't know how long they were working on it but the very top billed actors tend to make, what, 20 million for movies that take ~3 years to make.
So you assume the VC's only scored a 1x on this deal and had no special treatment for their preferred shares such as accrued dividends, liquidity preference, participating preferred, etc?
Most top actors spend 3-4 months on average per film. It's a scheduling things where you need a lot of people to film a movie some of which have offers for 3-4 movies that year. So people are working 12 hour days in one short burst and a lot of time in editing / post production but there is a ticking clock because investors want their money back ASAP. Reproduction can be slow simply because there is not a lot of money involved in the project yet.