Consider what the full experience of leaving Earth and going to Mars might be like. What could be intentionally added to the experience?
The first experience would be the launch. At three gees it would be about the intensity of a Gravitron ride at a theme park.
At low Earth orbit one would be able to dock with an orbiting habitat where one would stay for several weeks experiencing weightlessness and viewing our lovely planet one last time.
By the time we're ready for people to go all the way to Mars, low-cost transportation to the Moon will likely also be developed. Why not visit the Moon on the way? It starts with a flyby around the back side of the Moon where one gets to experience their own Earthrise.
Now we take the lunar ferry (fueled with propellant derived from lunar ice and you get to stay in a lunar hotel for several weeks with the increased freedom of activity that 1/6th gee permits. You would also be able to visit the an historic Apollo landing site.
Next you take the lunar ferry to an EML staging point where you dock with and transfer into the interplanetary ship for a 6-8 month journey to Mars.
Consider first staying at a facility at Phobos and skimming across its surface before heading down to Mars.
There is much that can be done to increase the quality of the retirement life on Mars. Take for example this concept:
True, you can get this sort if lifestyle on Earth without the high cost. But at least this demonstrates that life on Mars need not be spent in a cramped aluminum cylinder.
Consider other amenities including being able to visit the spa, indoor swimming pool, and participating in the activities of the active retirement community.
Hit the green at the indoor golf course:
Then, consider a caravan of shielded Martian "Winnebagos" which would explore the surface of Mars.
The retirees would be able to stay at interestingly-designed hotels a day's drive apart. Consider a Mars Casino as one of those hotels.
The following are experiences which cannot be had on Earth, at least not in real reality.
The retirees could stand on the rim of the largest canyon in the solar system.
Be driven up to the top of the largest volcano in the solar system.
Stand on the middle of the three volcanoes.
Hike up the so-called "Face on Mars".
Visit the Viking lander site.
Perhaps visit the very spot where off-Earth life was first discovered.
I could imagine that there might be some who would find such a retirement interesting and worth paying for. They would also know that their retirement contributed to a new world with the potential for backing up humanity and new experiments for civilization such as a libertarian nation or whatnot if so desired.