> Things like LRC circuits don't make sense without an oscilloscope. I have one now but REALLY wish I had one as a kid, even a crazy-cheap incredibly low quality one would have been amazing.

Yes. Especially since oscilloscopes now start at $43 at WalMart.[1] $36 on Amazon. There are $12 oscilloscopes on Alibaba. Bandwidth is low, but plenty for audio, motors, etc.

Here's an electronics kit recommended on Reddit.[2] That plus a cheap scope and you can do most of the basics. All for under $100.

[1] https://www.walmart.com/ip/Osdhezcn-Pocket-Size-Oscilloscope...

[2] https://www.reddit.com/r/AskElectronics/comments/1k06mpz/sho...