Yes! Maybe I'll build a premium customizable version out of it. Do you think that'd be useful? Bing charges around $5 per 1000 searches, so the premium version would be around the same (with caching covering hosting, maybe).
I think I might be willing to pay some amount of money for it, but not very much. I think a lot of other people would be willing to pay decently.
If you want to be cynical, just do Bing/DDG searches over Tor, and scrape that into the cache. This is $0/1000 searches, though it obviously violates some ToS somewhere. Unless they want to block Tor, you should be good.
With caching, I think you might be able to reduce the load.
Also, why is w3fools in the list? It's an awful site.