Sounds like what you really want (even if you don't realize it 😉 ) is to use a database to store your catalog data. Then one PHP page could be used to display each catalog item simply by adding a URL query string to pass the identifier of the item to be displayed, e.g.:
http://www.example.com/catalog.php?item=21
Then you would do a database query in the catalog.php page to select the data for item number 21 (in this example), and display it in the HTML output.
