What others have said. Doing the traveling spiritual teacher thing -- no, make that an itinerant speaker / teacher / seminar maestro on any topic -- in a legal and dignified way for a first world country, doesn't sound cheap to me. There's the rental of halls, the staffing of events, the movement of people and materials over great distances, and the publishing and promoting end, to name just a few things that cost money. And hundreds of dollars for a week of face time with the dude? That's a bargain when you consider the hundreds of dollars you'll pay for an hour of many quality, qualified experts' time across many fields. Even a college professor's time (which is a better comparison, since both involve face time shared with a roomful of other payees) is more expensive than this.
So it comes down to this: are these spiritual teachers you've looked at really experts on their topic, in your estimation? If so, then they command the prices they charge, like any expert. If they're not that great, then they don't deserve your money, and you probably should quit reading them, to say nothing of going to seminars with them.
Always judge a spiritual teacher on whether they practice what they preach.