Electronics or fabrication? Because you can get started seriously in electronics with under 500$ worth of dedicated tools. You need a good multi-meter, soldering iron, proto-board, bench-top power supply and assorted tools. The oscilloscope is neat but I've been doing electronic integration for close to 10 years now and never 'absolutely' needed a fancy one (I have a cheap 100$ portable one). Unless you plan on working a lot with radio frequencies and complex discrete circuits then it's a must, but if you plan on doing mostly Arduino integrations then it's overkill.

For fabrication it's basically an infinite well... My workshop is edging the 5 or 6k in worth now and the list of things I 'need' is only getting bigger. But a good set of basic tools (pliers, cutters and bits) will get you a long way. Rotary tools are super versatile and cheap, and a 3D printer can let you take a LOT of shortcuts for when you're missing fancier machine-tools and they're insanely cheap now.