Isn't Xenon infamous for being ridiculously expensive? It's the best general anesthetic by a mile since it's a noble gas, but we don't use it because the cost would be absurd. While the amounts used here must be small, and you're going to be stacked if this is how you're approaching Everest, it must still cost a small fortune — and turns out it does:
> One session of xenon gas costs $5,000 per person for a 30-minute session.
> One session of xenon gas costs $5,000 per person for a 30-minute session.