Ruby Price Comparison Script

I am looking to create a textbook price comparison site for the university I am attending currently. It would be a service similar to that which [login to view URL] provides with an additional component that allows a user to post books they are looking to sell directly on campus (something similar to how [login to view URL] operates.)? The script would query the major online book retailers by ISBN and sort the results from lowest to highest.? All the affiliate book sites that the script would query provide API examples, so the script should be easy enough to develop. Ideally I would like the script to be coded in Ruby, but I am not 100% set on it. I've been quoted $75 from a Ruby developer friend of mine. Therefore $75 will be the maximum acceptable bid.