An Amazon Product Rank and Daily Sales Tracker

Hello, I'm seeking a programmer/developer to help me build a tool that will monitor and track both rankings and daily sales of products at Amazon. The data necessary to create such a tool can be accessed for the most part via web scraping. This tool would must allow subscribers to buy access (subscription based) via Paypal. Subscribers would enter their product ASIN number(s) and keywords and thereby track any products daily rank (in Amazon search) and daily sales (of their product and/or a competitors product). Just and FYI, sales data is discovered via Amazon’s checkout cart, whereby if you attempt to order 999 of any product, Amazon reveals the available inventory in stock. So if a product has 400 in inventory yesterday, and 390 today… it can be assumed that 10 sold. It’s not a precise measure, and if there is more than 999 in stock it will not work, BUT… the data, even though somewhat limited is extremely valuable to Amazon sellers. Further more, the tool will analyze and discover new trends in amazon with daily analysis of products positions to detect newbies and growing trends. *See links to existing similar tools in private message area.