The Ultimate Marantz, Superscope, UNIX Boombox Thread

Hello, I'm new to the community and happened upon this forum while researching a new find, a Marantz PMS-3040. It appears fully functional, but the cassette motor is, sluggish, so I'm trying to figure out if it's worth it to replace the belt or just sell it. It seems like a very cool machine. But thought it'd be good to check in with this forum for advice. Thanks!