$a =~ /\d\d\.\d\d/ || $a =~ /\$\d\d\d\.\d\d\d/ || $a =~ /\$\.\d\d/

##</code><code>##

    $a =~ /\d\d\.\d\d/ || $a =~ /\$\.\d\d/;

##</code><code>##

    $a =~ /(?:\d\d|\$)\.\d\d/;