Book series about preparation for a war at the Singularity

Question

I am looking for a book series (almost certainly a trilogy) that starts with some humans in a space station being abducted by a small funny-looking alien and taken to a prison planet. They find out that the way space travel works is by creating copies of the passengers, and the originals remained on the space station. This is actually good for the aliens since they believe every sentient being will resurrect at the Singularity and will be forced to fight a battle, so the more the merrier.

The one other detail I remember is that the world economy has a rampant inflation, so people take any cash they have at the end of the day and buy 20th-century memorabilia that doesn't devalue as much.

Answer 1

Pretty sure this is The Eschaton Sequence, starting with The Other End of Time by Frederik Pohl.

The Goodreads description verifies the basics:

his latest novel features Dan Dannerman, a poorly paid government agent in the not-too-distant future. Dannerman discovers aliens on an abandoned space station and is drawn into a conflict that encompasses the universe. According to one of its protagonists, the war Dannerman blunders into centers on what "ordinary people have been used to calling 'Heaven.'"

Other reviews there confirm various other details:

Not very thought provoking, aside from the annoyingly unrealistic paradox of what to do when you meet with your exact duplicate (not a clone, but a quantum-accurate copy of yourself). The plot worryingly revolves around a real astrophysical "heaven" where, after the big crunch, all living things are reborn and share eternal life together.

Including inflation:

By necessity, everyone carries guns for their own protection. Inflation has become so devastating that every day it's necessary to convert unspent cash into commodities/collectibles. Florida has more or less seceded from the U.S., etc.