JSFiddle - React, Tailwind, and code Playground

HTML

<div data-plusminus="25" id="clickThis">Click This</div>
<div id="cost">25.00</div>

JavaScript

$("#clickThis").click(function(e){
    var addThis = parseInt( $(this).data('plusminus') )
    var newVal = parseInt( $("#cost").text() ) + addThis;
    $('#cost').text(newVal);
    $(this).data('plusminus', addThis * -1);
});