The PC's haven't done anything yet -- if I'm understanding the post right -- it's just the NPC's he's made some rolls for (to gauge the danger of the climb, the danger of the fight with Harpies, etc).
I wouldn't consider this to be an Extraction, because those generally are, well, kidnappings/escort duty rolled into one. An Extraction, in Shadowrun parlance, is a job wherein you go onto -- as a for instance -- Renraku turf to steal a Renraku employee (one worth stealing), and then take them back to your Fuchi or Ares or whatever Mr. Johnson, who now has himself a new top-tier researcher.
This is...more of an object retrieval, albeit one that's apparently pretty dangerous. Depending on how far the trip is, how long it's likely to take, etc, I'd say 20,000 might still be a fair amount (a little high for some groups, but it depends on how far into the campaign things are) of pay, don't get me wrong...but it's more of a smuggling run/escort/destruction mish-mash than an Extraction, though.