Of course you can. You just cannot do it openly.
It would be very easy for people in St. Mary's to accept offers for their house from other Traditional Catholics, especially if they were working through a Catholic Real Estate Agent.
"His financing seemed more in place", "they had what looked like a shorter chain", "their buyers were cash, so we felt happier about their offer", "they did not want to move in till September which suited us better". "They wanted to move in next month, which suited us better".
What actually happens, of course, is that the pagans offer a few thousand more for the property and greed means the Catholic seller takes the pagan's offer. They don't care because they are moving out of town anyway.
If everyone worked for the good of the community and put their selfish interests second then you could build a little peace of Traditional Catholic Heaven.
But people don't do that do they. They convince themselves that Hitler was not really such a bad chap or that the Jєωs are all evil or that women in trousers are evil feminists intent on castrating them and stealing their children. The young priest who turns up to serve them is too liberal or too sympathetic to Bishop Fellay's point of view.
These dream villages simply attract kooks. Balanced people, like me, who could be tolerant of the foibles of others, start new businesses, organise, employ people, would never sign up because we know what would happen. Within a year I'd be accused of being mercenary, or anti-distributionist, or liberal, or heretical or anti-royalist or some other crap.
The rich already have villages like this. They are called gated communities. They work well because they all have a common purpose. To stay rich and keep the riff-raff out.