That part of the population can take the other route proposed -- like thousands of "hippie travellers" each year: go at it with just the ticket and the kindness of strangers. Having some skill you can use to make some small money here and there (like playing music on a street corner) helps.

For the rest, those making $50.000 a year or more, $5000 to $10000 is very doable to save in 1-4 years -- if you actually want to visit the world that is, and not just want it to fall on you lap while you enjoy everything else at the same time. Rent a smaller house, don't buy a new car, spend less on bars, restaurants and other BS, dont buy that iPhone, etc.