The planet’s gravity is not what is causing the time dilation, but rather the gravity of the supermassive black hole that it was orbiting. The black hole is somehow spinning extremely rapidly, causing frame dragging, which creates a particular stable orbit very close to the event horizon.
Apparently the energy requirements of the orbit would preclude ever reaching the planet except by slingshot manoeuvres around intermediate size black holes or neutron stars.
This would amount to an annual tax rate of 2.6% which is possibly some of the highest property tax rate in all of the United States. The median property taxes paid by homeowners in the US is only $2000 per year.
I agree that real estate as an investment is generally not the best option, but I don’t think that says anything about real estate as a wealth building tool for the middle class. If you compare renting to buying using a mortgage (the typical options) over, say, a 50 year period, buying will almost certainly come ahead in terms of wealth built.
For a primary residence that you plan to occupy long term, i would recommend buying almost every time. If you’re looking to build more wealth after that, I think there’s usually better options than e.g. buying a second house and renting it out.