Oh boy, this is a great topic to respond to!😍
Since retiring a few years ago, I've treated myself to quite a few secondhand (and also a few new) basses (plus a couple of guitars too !). The unexpected goodies that these bad boys have turned up with over the years never ceased to surprise me. I can remember: two hard cases, several gig bags (of various quality and condition), numerous straps, leads, and picks, two decent electronic tuners, spare strings, a microphone, a pedal, and even an e-bow (okay, it wasn't working!).
Sadly no hidden cash though 😂😂