Some users get a huge load of reputation with little effort. Probably, that's mostly due to some weird voting effects, where a question is upvoted unreasonably high. Yet, it would still be interesting to see, which users would actually win a badge indicating that they have asked / answered few questions and still got a lot of reputation. An (extreme) example user:
https://stackoverflow.com/users/1127571/honza-brabec
1 question, 1 answer, 1386 repuation! Maybe the badge would be awarded to those users that
- Have asked/answered at least 10 questions (to avoid weird effects, i.e. the above user shouldn't get this badge)
- Have gotten an average of 20 upvotes or +200 reputation (example) per question/answer
This would be a bit similar to the legendary badge, except that the measurement is less absolute.
Hmm... This might be a duplicate of this: New Badge Suggestion for high average scores on answers. In any case, it's related
Note: You may think that badges should encourage behaviour. But then again, there are already many badges that just award arbitrary things that a single user cannot influence: