my @Strings =
  (
  '$3,023,123.34', '9,876,453', '123456.78',
  "4,33,234.34", '$1.234', "abc",
  "1,0000.00"
  );

my $Payment;
foreach $Payment (@Strings)
  {
  if ($Payment =~ /^\$?(\d{1,3}(,\d{3})*|\d+)(\.\d\d)?$/)
    {print "Match: $Payment\n";}
  else
    {print "Fail: $Payment\n";}
  }

Output:
Match: $3,023,123.34
Match: 9,876,453
Match: 123456.78
Fail: 4,33,234.34
Fail: $1.234
Fail: abc
Fail: 1,0000.00
Match: 199999.99
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