Actually there is no difference between search page result sites like the OP and what you said. Having a URL that ends in .html does not mean there is a static html file on the server. For examples, nextag and pricegrabber have URLs like blah.com/digital/Canon-EOS-7D-SLR-Digital-Body/m739295014.html. Scroll around these sites and you'll see they're anything but static.
Each page is simply a result of a query. Whether the database is local (like nextag) or remote (like Amazon API query like OP) is inconsequential. Personally, I would be VERY happy if Google hid/ignored these kind of search-query sites. I have not once found any of these sites useful. Problem is the large gray area in which these sites operate and what I find useless, someone else might find useful.