Is there a word for a great price paid in exchange for a great gain?

Question

For example, let’s say that, in return for a Ph.D., the hero had to give up ten years of life. I’d thought of calling that a blood price but maybe there’s a better word? Seems like maybe some Saxons or Picts would have worked some quite dramatic tradeoffs into their folklore – so, just like Irish folklore gave us the wonderful word geas, maybe there’s a short, non-Latin word for a … (substitute in for blood price) … .

Answer 1

The term sacrifice is used to convey the giving of something important. Originally used to refer to gifts to gods, it is now used in any context of a great giving, usually for a highly valued gain.

Answer 2

How about Pyrrhic? It doesn't have an implication of necessarily great gain, but the great cost is there.

Wikipedia:

A Pyrrhic victory (/ˈpɪrɪk/) is a victory with such a devastating cost that it carries the implication that another such victory will ultimately lead to defeat.