The only time I have ever done the "bad thing to do after jail breaking that can get posts locked here for even talking about" was so I could get an app that Apple removed from the AppStore because it violated one of their AppStore terms. Remember that free wifi tether app, or MiTube? Stuff like that. And even then, the needs that I had back then are no longer needs I have now, and apple hasn't done the ban hammer in quite some time.
Now I only jailbreak for special features. Enhanced status bar, dock, home screen, phone blacklist, HTML widgets, etc. I've probably spent $100 or more on Cydia apps so far. I fully support developers.