Hi.. Interesting project. I did similar project last year. This is a web application written in ASP.NET MVC using MWS API
User will submit an excel sheet that contains UPC,ASIN or ISBN (Search by Keywords is possible). It will output, Number of New,Used offers, lowest selling price (with shipping). But it wont explicitly tell the number of FBA offers(not supported by API). FBA fee calculation for the item, Rank etc.
All the submissions will go in a queue. And server application will process them one by one. multiple users supported. Email notifications when input submitted and output generated.
Let me know know.. We will discuss