JSFiddle - React, Tailwind, and code Playground

HTML

<select name="sel_tlcb" id="sel_tlcb" class="selector" onchange="mostrar(this, 'Tarifa');">
    <option data-description="35€" value='1000' >&nbsp;&nbsp;1000</option>
    <option data-description="70€" value='2000' >&nbsp;&nbsp;2000</option>;
    <option data-description="100€" value='3000' >&nbsp;&nbsp;3000</option>;
    <option data-description="150€" value='4000' >&nbsp;&nbsp;4000</option>;
    </select>
<div id="Tarifa" class="tarifa"></div>

<select name="sel_tlcb2" id="sel_tlcb2" class="selector" onchange="mostrar(this, 'Tarifa1');">
    <option data-description="45€" value='1000' >&nbsp;&nbsp;1000</option>
    <option data-description="80€" value='2000' >&nbsp;&nbsp;2000</option>;
    <option data-description="110€" value='3000' >&nbsp;&nbsp;3000</option>;
    <option data-description="180€" value='4000' >&nbsp;&nbsp;4000</option>;
    </select>
<div id="Tarifa" class="tarifa"></div>
<div id="Tarifa1" class="tarifa"></div>

JavaScript

function mostrar( obj, nameDiv ){
    var container = document.getElementById(nameDiv) ;
    var description = obj[ obj.selectedIndex ].dataset.description;    
    container.innerHTML = " Item seleccionado.. " + description;
}
mostrar(document.getElementById("sel_tlcb"),"Tarifa");
mostrar(document.getElementById("sel_tlcb2"),"Tarifa1");