This stuff absolutely doesn’t need to be expensive. I was doing electronics for a long time now. I guess I am at professional level but I never got regular 9-5 job doing electronics, I was always doing odd jobs like repair, design, construction.
I only recently got modern tools for this. For years my books, parts, tools and methods were mostly from 70s/80s that I got from various public dumps. That was 10 years ago though, now these places are closed.
If you need to do something really fast and cheap - draw a pcb with sharpie and use ferric chloride to etch it. Modern oscilloscope is a luxury. Since I was working mainly with audio stuff I had a diy amplifier with a speaker connected to it that I used to listen to waveforms.
A lot of tools can made by hand too. There is a ton of old projects for old atmega microcontrollers. One of the best projects like this was sold as generic chinese made “multipurpose tester” which - last time I checked - was not properly designed when looking at the original. Original would this one - www.mikrocontroller.net/…/AVR_TransistortesterBut everything necessary for this project is here - github.com/svn2github/transistortester/…/master