Let me formulate it like this: The most expensive series so far was The Pacific, with a budget of $22 million per episode [0]. You'd expect a high budget series to spend a lot on actors and directors - let's just go with 50%. This would put this series on a budget equivalent of $800 million to $1 billion with a "normal" cast (depending on how much you calculate as budget for lesser known actors). Given 20 episodes [1], this comes down to an equivalent of $40-50 million per episode. Even extremely high production value series like GoT were well below this number. Just going with the actual number of $23.25 million per episode already makes this one of the most expensive series of all time.

Now, this doesn't necessarily mean it's going to be bad, but having a lesser experienced cast burn through that much money smells like bad management and could therefore be an indicator that the series is highly over-produced with not much content to go with it. Of course, time will tell, but the lack of known-good talent in the management and the insane amount of money spent don't make me overly optimistic.

[0] https://stacker.com/stories/3159/25-most-expensive-tv-series...

[1] https://www.slashfilm.com/568297/lord-of-the-rings-season-1-...

The Pacific was definitely not expensive because of its cast (none of the leads, Sledge, Leckie, or Basilone, were well-known). You can just watch the show and see where the money went.