I just bought a personal IDE licence a few days ago. JetBrains makes one of the best IDEs I've ever used, and I consider that 100€ well spent.
Absolutely money well spent.
But that's not why I stopped using JRebel, I stopped using JRebel because 10 years ago I worked on monolithic code bases that got deployed to application servers where a build and deploy cycle took 30 minutes, if I did the build with no unit tests. Even though it took constant fiddling to keep JRebel working and a hot deploy worked on maybe half the changes I made, it saved me many hours.
Now I work on microservices with embedded app servers where a build/deploy cycle is 30 seconds, no need for JRebel. Sorry sales guys!
I'm delighted that their smarts and dedication in building a high-quality, user-focused product has paid off in a big way for them.