I think the real cost will be the broadband. The whole map is 2 petabytes large, so each area has to be loaded seperately which will take up a lot of space.

Its probably not too bad. You only see a tiny slice at a time. They must have pre-cached regions, as you specified ahead of time where you will fly.

In the meantime, I would really urge you to travel and see the beautiful sights and places which you might not be able to later on. Splurge a bit and see those places so you can have a memory of them and never have the feeling that you missed out on anything in life. The Great Barrier Reef, The Grand Canyon, visit a space observatory so you can see the other planets, other galaxies, etc.,

Especially considering your age, I would really really urge you to do this. If you dont have anyone to go with you; just do it solo. I hope you consider my suggestion.