In 2000, KONAMI offered a limited run of 100 total units of a hard, stainless steel Dance Dance Revolution Arcade-Style Controller sold to customers on konamistyle.com for about ¥198,000. There was not much information about the controller since its release, but a Japanese rhythm game enthusiast @gc_hisakunchi had one in possession and wrote up a blog post with photos and details about the super rare controller. Check it out here.
https://twitter.com/gc_hisakunchi/status/988068774933770241