JSFiddle - React, Tailwind, and code Playground

HTML

<span class="price">500</span>
<input type="checkbox">

CSS

.price {
    display: block;
    width: 100px;
    height: 30px;
}

JavaScript

var checkbox = document.querySelector('input');
var price = document.querySelector('.price');
checkbox.onclick = function(){
    if (checkbox.checked){
        price.innerHTML = "1000";
    }
    else price.innerHTML = "10790";
}