Kanto Railway will be selling its DD502 diesel locomotive, which was built in 1956 for 2 million Yen (taxes and delivery extra). The obvious caveat is that it is not in an operable state (engine doesn't start and most of the safely/signal systems had been removed) as it had been sitting in the Mitsukaido Yard since last operated in 2007
https://www.kantetsu.co.jp/img/news/2020/20102301_train/info.pdf