Built am Amazon to eBay Scraper

Build a Scraper which can find items on Amazon which are NOT available on eBay. Must be built with a good API as it will be transitioned into my current software as an addition. I'm not entirely sure how I would like it to work but I know that I would like to select a combination of different search perimiters and I would like to search manually, not cron. One problem i am not sure how we are going to overcome is that a lot of Amazon items ARE listed on eBay but under slightly different titles and keywords, how are we going to filter these ones out of the search results? Things i would like to be able to search: Amazon items that are prime or free delivery, which are NOT listed on eBay UK. Amazon items that ARE on eBay but at a cost of at least 40% more and no more than 5 other eBay users selling them. Things i would like to filter out of the searches: Amazon add on items Amazon special offers I may have more suggestions as the project progress' I don't want the search to be based on text or 'keywords' I would like the search to be a combination of drop-down boxes which can all be differently selected to provide the results. If you would like to see a version of my current software which this app will be encorporated into please ask.