It's not the most expensive overall Star Wars prop however: https://www.dexerto.com/tv-movies/mark-hamills-original-star-wars-lightsaber-sells-for-record-breaking-amount-3388030/

Mark Hamill's original Luke Skywalker lightsaber has sold at auction for a record-breaking $3.75 million It is now the most expensive screen-used Star Wars prop ever sold at auction

It's not the most expensive overall Star Wars prop however: https://www.dexerto.com/tv-movies/mark-hamills-original-star-wars-lightsaber-sells-for-record-breaking-amount-3388030/