Inside a double-quoted string, put a back-slash in front of "$" to get a literal dollar-sign:

        print "A sample dollar amount: \$12.34\n";
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Or, simply use single-quotes, and don't use a back-slash:

        print 'Another dollar amount: $56.78', "\n";
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Or use the q// quoting operator, which works like single-quotes:

        print q/Yet another amount: $90.12/, "\n";
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There's a whole section in the perlop man page titled "Quote and Quote-like operators." That's something you'll want to read.