Sci-Fi book or short story about a man who travels to the future using time-dilation and his accumulated wealth allows him to purchase a ravaged (Earth?) in order to repair it.

[Thow]

I read this between 10 and 20 years ago. I don't believe it was a "time travel" story per se, more of a space travel at relativistic speeds story where the traveler doesn't age much but his home planet (Earth?) does. During his journey he becomes obscenely wealthy and decides to use his wealth to buy his home-world. The planet has become mostly uninhabitable, so he buys the planet in order to rebuild/repair it.

Thanks for any help.

[Justanotherbiblophile]

Is he traveling in a space-ship (in space), or is it some type of device (on a planet's surface)?

Do you know the nature of his wealth? Compounding investments (managed by an AI, perhaps?), inheritance(s), or profits on innovations he developed?

[Thow]

I believe the wealth was achieved passively, probably compound interest, but that point didn't stick with me. I don't remember an AI character, so if it was AI managed wealth it was not a memorable character.

[Andy]

I wonder if you're thinking of Nostrillia by Cordwainer Smith Norstrilia which features the purchase of Earth

[David]

Is the Earth purchase an end objective (that is, happens toward the end) or the purchase happens early (maybe even appear in the cover) and he has to deal with whatever consequences come his way?

Is important/known how the Earth has become uninhabitable?

Edit: err, forgot to ask. Who\what does he purchases Earth from?

[Andy]

I haven't actually read Nostrillia unfortunately, so I don't know the answers to those questions.