edit: Google is not doing the best at searching, they are doing the best by budget current economy allows, to be better than Google you have to cut cost of operation in very dramatic way, so you can expand the beyond where Google stands now, other than that, you can't outperform Google.
I don't think it would be a good business decision for Apple though, and there's no guarantee that they could even get there with throwing billions of dollars at it.
There's absolute no way they can do, Maps is very very expensive to operate, to be successful you have to be better than Google and that require none existing technologies (such quantum storage).
It is very hard to catch up with them.
So, Apple would need a "good enough" search engine and they'd buy DDG over a cup of coffee. Invest in improving it. And, yes, they're for sale, just as Microsoft or Exxon is (for the right amount of money)
Sorry, what? Can you clarify?
if that happen, it would be possible to INDEX all of internet at very low cost and being competitive with Google. just think about how much it cost Google or BING to index 1 billion static pages.