space tourism will become much cheaper very soon, the last 3 weeks we have had massive accomplishments in space. To get comfortable going to another planet, surely people will need to be normalized to the idea of space, which is what the value of space tourism is, besides the obvious superlative nature of it.
That stuff costs money and if you're only launching 5 people at once, it's still a high sticker for each launch. While "regular" vacation scales pretty well with the number of people you're going with, it's not going to be the case for space exploration.
On a regular vacation, most of the cost overhead for each additional person is the transportation cost. Here, the vacation _is_ the trip