The whole point of WC is that they're supposed to raise the money themselves, and the school is supposed to work with them to create ways in which they can fundraise - so it's more of a team effort to raise the money rather than an individual thing.
DS2 is older, and will be going to Iceland next year - so we've been given 18 months to fund raise as well.
And it does, apparently, (certainly at this age) count for up to 70 points on your UCAS application, which can only be a good thing. (Trust me on this one - having an older son going through the whole university application process at the moment - we would fall on 70 points!!!)
And without knowing the details of the challenge, I would say that there are lots of things that make it a challenge - they will probably be wild camping, not pitching the tent in a nice, facilities-loaded campsite, and will have to shop and cook for themselves using basic equipment - I think that's a fantastic experience.
They also work on building team-working skills as well as leadership skills.
And - heaven forfend - it might actually be fun.
If they can raise the money themselves (and I appreciate that's a big 'if', especially if the school isn't helping as much as they can) then I think it's a fabulous thing for them to do.