metal used to manufacture the ASICs will still cost money right?
but it won't matter when one of those reach roi, because that roi can pay for the new machine and so on, also i believe that aside from the chips everything else has not an heavy cost, on the opposite is very cheap
And the chip is also only expensive because of the R&D and relatively low volume compared to consumer grade chips.
What about a modular ASIC where you only need to swap the chip? That would make everything cheaper, including shipping.