Write a Script that retreives average selling price of games on ebay

I need someone who can write a PHP script which will take the name of a video game that I give it and will retrieve the following data from ebay: -Average sold price used and loose -Average sold price used and complete -Average sold price new I have a gaming website that has data for 10,000s of games, everything ranging from the Atari 2600 to the Xbox 360. I want to be able to retrieve all this data for each game so that each game page on my site has a price guide of what the game is worth loose, complete and new. The script needs to be as accurate on the game. For example, when the script finds the average selling price for "Super Mario Bros" for the Nintendo NES, it cannot include "Super Mario Bros 2" or "Super Mario Bros 3" and likewise, if the script was to find the average selling price for "Super Mario Bros 2", it cannot include "Super Mario Bros" and "Super Mario Bros 3". Also, some systems have games of the same name, the script should be able to filter out games with the same names on other systems. The script needs to also be accurate on the condition. For example, when the script finds the average selling price for a used and loose copy of "Super Mario Bros" for the Nintendo NES, it cannot include used and complete copies or new copies. Likewise, if the script was to find the average selling price for a new copy of "Super Mario Bros" for the Nintendo NES, it should not include a used and loose copy or a used and complete copy. FYI, loose means game without the original case or box and complete means with the original box or case and manuals. REQUIREMENT: Before I'll consider hiring you, I'd like for you to tell me how you plan to go about this. Ebay does let you view completed listings for the past 90 days.