Julian Rippon Aug 21, 2012:

Given that there are only a handful of hits in Google (excluding those which are actually なにげ　だいたい〜）and none seem to have anything else written in an unusual dialect, I would tend to agree that it's probably just a typo for にげだしたい rather than a deliberate abbreviation. Could be wrong though.

naruru Aug 21, 2012:

Possibly a 宮崎 dialect!

mommamia Aug 21, 2012:

I think it's just a typo, since にげだいたい and にげだしたい have the same amount of characters so I don't see how it could be an abbreviation. Then again, maybe there's a dialect that uses these words? (but that would be mentioned in the source text) I'm also very curious to know what the answer would be.