Yep, the others are right. That's extortion.
Pack a bag (smallish, 3 of everything
) and jump on a plane with either a round the world or just focus on one continent and get much cheaper flights.
If you spent the whole year in, say South America, you'd come back speaking Spanish, a changed man, and with stories to tell for ever. The only danger with backpacking is that you end up following the droves from one party to the next
and never actually soak up any culture/ do any outdoorsy stuff so make sure you have objectives when you set off.
For the work option, offer your services to any of the charities working in the area you're interested in and they might put you up for free labour. Often smaller is better as large charities have stricter employment criteria, lists would be available from the nations' government offices.
I've done both of the above with great success, although I never had the luxury of a whole year to play with.
Alternatively, don't let us nay-say you out of the paid-for trip if that ticks your boxes. Sometimes these organised trips are the best way to get involved with a culture at a 'deeper' level. Especially at your tender age when the red-tape around organising it for yourself can be daunting.
You'll have the time of your life whatever you choose and I am sorely jealous - maybe the boss would give me a sabbatical if I asked nicely...
