my $price = "50";
my $htmlvar_qq = "<li>The price is \$$price</li>";
my $htmlvar_q  = '<li>The price is \$$price</li>';

print "$_\n" for $htmlvar_qq, $htmlvar_q;

##</code><code>##

<li>The price is $50</li>
<li>The price is \$$price</li>