First, use strict; and use warnings; (or -w). Secondly verify that your code is written as intended, particularly the line:

if ($line =~ /class=\"fifty\">([^<]+)<\/a>/) {

Since <DATA> doesn't contain the string class="fifty" the test fails. I can't infer what you intended from the above code, but it would seem to work as-is, just not in the manner you anticipated.