my %regs = ( "site1.com" => [ "price", qr{prices: <table>(.+?)</table>}is ],
             "site2.com" => [ "cas", qr{cas: <b>(\d+-\d{2}-\d+)}is ],
          ...
            );
...
foreach my $site (keys %regs) {
    ...  # fetch data into $pagecontent...
    my ($key,$reg) = @$regs{$site};
    $thisHash{$key} = $1 if $pagecontent =~ $reg;
}