I think they could take a page out of ESO's book and only offer unique housing as a one-time fee on Mog Station. Yes, they messed up the idea that there would be enough houses for everyone with the current ward system. And it seems they have difficulty adding more wards - and I agree that it seems like we'd be "paying for their mistakes", but hear me out --

Putting those points into consideration, I think it would be worth entertaining the idea of "glamour housing" to go above and beyond the more traditional housing system. So something like a Coerthan cabin, a Xaela yurt, a home on a floating island in the Sea of Clouds, something unique that once you buy it, it's yours. The property would have to be in its own region which looks and works similar to current housing wards so you could still have a garden, chocobo stable, etc. But it would be in a more unique/exclusive location.

The payment would be a one-time fee that would grant you access to the area so you can pick out a plot. If you pick out a plot but don't build on it within 30 days, it gets relinquished. This would be to prevent people from buying up mass plots in an area to hold onto. You also wouldn't be able to sell these plots to another player for in-game money. Non-refundable, non-transferable.