JSFiddle - React, Tailwind, and code Playground
HTML
<select id="t_dermal_name">
<option value="t_default_dermal">-- Choose --</option>
<option value="1" rel="30">Between Eyebrows</option>
<option value="7" rel="30">Individual Line Softening</option>
<option value="2" rel="30">Lip Contouring</option>
</select>
<select id="t_wrinkle_name">
<option value="t_default_wrinkle">-- Choose --</option>
<option value="1" rel="30">Between Eyebrows</option>
<option value="7" rel="30">Individual Line Softening</option>
<option value="2" rel="30">Lip Contouring</option>
</select>
<span id="output"></span>
JavaScript
function onSelectChange(){
var total = 0,
dermal = $("#t_dermal_name").find('option:selected'),
wrinkle = $("#t_wrinkle_name").find('option:selected');
if(value = dermal.attr('rel')){
total += parseInt(value);
}
if(value = wrinkle.attr('rel')){
total += parseInt(value);
}
$("#output").html(total);
}
$("#t_dermal_name").change(onSelectChange);
$("#t_wrinkle_name").change(onSelectChange);