Suggest Free API Alternatives to Bing Search - repost

We used these search results in our own search engine to dynamically generate SEO friendly pages with ads. However, Bing is no longer free and very costly. We need your help to find a FREE web search API alternatives to above. Your Web search engine need to show up to 1000+ results per search like google and all the big search engines does! It is important that the API you suggest may be used for FREE and for a COMMERCIAL site. You need to show us a demo page where we can test your web search engine API, or we need to try it before we pay you! If you don't have this kind of web search engine API, please don't contact me!