Sun-Sentinel.com published an article today about Google's new low cost search engine services. For $100 / year, Google will search through up to 5,000 web pages and for $500 / year, Google will search through up to 50,000 web pages. Unlike the current Google site search service, these search results, I think, would exist on your site as if it was your own code without Google-served ads (such as those found in AdSense for search pages).
This is pretty cool. $100 / year works out to be about $8.30 / month. Not a bad cost for Google-powered searching. I know that creating solid site searches is one of the things I find the most difficult. I am sure their solution will be better than my solution just about any day of the week! Although, I wonder how the search results are returned.