Actually, depending on what you're actually trying to accomplish, something other than XML::Parser might be a better fit. In particular, XML::LibXML is vastly superior (IMHO). There's more documentation to look at, but in my experience, it's worth the effort, especially when you get to the XPath stuff.

Here's how I'd use XML::LibXML for that same simple example (to print out just the contents of "Amount" tags):

#!/usr/bin/perl

use strict;
use warnings;
use XML::LibXML;

my $parser = XML::LibXML->new;
my $doc = $parser->parse_file( "org1.xml" );

my $xpath = XML::LibXML::XPathContext->new( $doc );
for my $node ( $xpath->findnodes( '//Amount' )) {
    print $node->textContent, "\n";
}
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It doesn't get much simpler than that!