$50 is a number for LEO (Low-earth orbit). $/kg to a Moon orbit (or flyby) might be significantly more expensive. Not that, because it is further so it needs more fuel, but also it is a few days trip which would need a bunch more kilos in provisioning food, water and other things. So yeah, unfortunately not that cheap to have a honeyMoon in the moon (heh)

There is a lot of possibilities to make a trip to the moon cheaper though. If we make LEO that cheap, we can build a lot of infrastructure in the space that would make the tourism to moon more affordable. Like keeping a few starships always in orbit as some kind of space-hotel-metro system.

This will probably take a few more decades, though.

Artemis by Andy Weir dwells a lot on this kind of infrastructure, but I never could understand the orbital mechanics described in the book.

Yeah it wasn't explained well in the book, but I did some reading of third-party sources and diagrams about the Uphoff-Crouch Lunar Cycler orbit, which helped (Wikipedia and the like).

Even if it cost 10x as much to reach the Moon it would bring the costs within range of mere multi-millionaires instead of billionaires.

That is true, I guess some weird multi billionaire might have a honeymoon there. We should see some other media as well, like movies perhaps, and of course p*rn

Only if you don't care about coming back!