I figure that sometimes these things get overly complex to the detriment of clarity. Maybe I'm guilty below as I allowed for Australian dollars vs US dollars...

Don't be afraid to use the Perl regex engine in a couple of lines! The speed of this thing in Perl 5.10 vs Perl 5.6 is stunning. GO FOR CLARITY first.

So talking thru the code below: (1) process only things that are US dollars (optional), (2) there is gonna be zero or more spaces, followed by the "$" sign and some sequence of digits,commas and periods. (3)that sequence gets captured and then the commas get deleted.

Update: If max valid dollar amount is $100,000.00 then I would enforce the 100,000 max via a numeric comparison on $number. BUT, this is actually the wrong place in the system to be checking that!

#!/usr/bin/perl -w
use strict;

my @bucks = ('$1,999,003 USD ', '$1,532.33 AUS', '$1,500.11 USD');

foreach my $amount (@bucks)
{
   next unless $amount =~ m/USD/;
   my ($comma_amount) = ($amount =~ /\s*\$([\d,.]+)/);
   print "c=$comma_amount\n";
   (my $number = $comma_amount) =~ s/,//g;
   print "n=$number\n";  
}
__END__
prints:
c=1,999,003
n=1999003
c=1,500.11
n=1500.11
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