In the end this is anecdotal, but I find electronics to be one of the cheaper hobbies to get into.
What do you really need in terms of tools to get started?
A soldering iron
Solder + Flux
(Good investment is a multimeter)
That's it in terms of tools. A bad (but working) version will cost you 20-30$. If you want a decently good setup (what I use I would describe as decent) is 120$ for soldering iron, solder, flux and multimeter. That's not very expensive as far as hobbies go.
Then the "running cost" will be the cost of the parts you use. Again, how wild you want to go is up to you. If you want a cheap project, that's a arduino nano (2$/piece), wire, sensors (~1-2$/sensor) and depending on application actors (starting at 3$/piece). Of course things can be more expensive depending on your project. If you buy parts from aliexpress etc. in packs of 5-10 they are dirt cheap.
Overall hobby electronics seem cheap in terms of upfront cost and only middle of the pack in terms of running cost.
And as >>781
said, if there's a makerspace, you can basically save the cost for tools. Also tools double as … well tools. Having a multimeter is a good idea either way to repair stuff in the house, and a solder iron can save you hundreds of dollars when you fix something that is broken.