I want to say that something is "expensive" in terms of time and resources

You should never use sacred to mean that it uses a lot of time and infrastructure. Other than simply using expensive, you could also use costly.

While A) may be preferred, B) and C) also offer advantages.

Sacred implies the metaphysical, and in physics/math/tech arenas the literal is seen as more accurate and trusted. As an additional reference, the Kiersey Inventory studies indicate that many who trust the visible and factual over invisible may be your readers, and they may bristle at use of the term Sacred.

Personally, I prefer humor, especially to achieve leaps in logic.