Are you certain something like this doesn't exist already? If there are 500-1000 sites I gotta imagine someone has already built this. Shopping feed / aggregato

Are you certain something like this doesn't exist already? If there are 500-1000 sites I gotta imagine someone has already built this. Shopping feed / aggregators are nothing new. e.g. http://searchenginewatch.com/sew/study/2097413/shopping-engines http://searchenginewatch.com/sew/study/2097413/shopping-engi...