My previous bass guitar had one of its machine heads snap off, and I had rehearsal that same day, so I looked online at the used instrument stock at local music stores and found a bass guitar used that was a very unique, discontinued model that I'd been essentially dreaming of for a while, and happened to be there.
What I probably should've done is replaced the machine head, which would've been a very quick and cheap fix, but I instead bought the new bass and then took it to use at rehearsal. Now it's my daily driver and I'm very glad I got it.
Edit: I fucked up and fixed the comment, somehow it double posted instead of just editing.
I'm a multi-instrumentalist and I now have 3 guitars, a bass, a banjo, two ukuleles, a sousaphone, trombone, trumpet, soprano trombone, bugle, clarinet, tenor sax, Roland keyboard, melodica, cajone, stylophone, otamatone, ocarina, concertina, and a recorder. My goal is 50 instruments by the time I'm 50.
If you can play sousaphone and other various brass, you might be able to pick up the didgeridoo. The embechure is kind of similar (see also: alphorn). It's the circular breathing I'm still trying to get the hang of.
And a I picked up a hand pan drum last month for giggles. It has a lovely tone.