Over the years, some props and costumes from “Star Wars” — or pieces of them — have sold well, while others failed to pique interest. In 2017, an R2-D2 unit from “Star Wars: Episode IV — A New Hope,” sold for $2.75 million. Last year, though, a light saber said to have been used by Mark Hamill in the first film was pulled from an auction after fans questioned its authenticity and the $200,000 price tag.

And in 2010, a Darth Vader costume made for “The Empire Strikes Back” — including helmet, mask and armor — was offered at auction and expected to sell for $250,000. No bidder emerged.

Sure, the early 2010s were a tough time for sellers of any kind. America was in the midst of a punishing recession, for one, and buyers fled the art and collectibles market. At the same time, interest in “Star Wars” wavered as it had been at least five years since the release of “Revenge of the Sith,” the last movie in the “Star Wars” franchise to be directed by George Lucas.

Since then, the franchise has expanded under the Walt Disney Co., which bought Lucasfilm, the production company founded by Mr. Lucas, in 2012. (Lucasfilm declined to comment on Wednesday.) What makes Mr. Eller’s costume notable, Ms. Williamson said, is that it was created by John Mollo, a British military illustrator and wardrobe consultant who designed the costumes for “The Empire Strikes Back” and “Star Wars,” the first in the series and for which he won an Oscar in 1978.

Born in London in 1931, Mr. Mollo had a particular interest in military outfits and also designed costumes for movies like “Alien,” “Barry Lyndon” and “Chaplin.” (He won a second Oscar in 1983 for the movie “Gandhi.”) Mr. Mollo died in 2017 and, last December, Bonhams auctioned off some of his artwork, including original sketchbooks for “Star Wars,” which sold for $162,583.