JSFiddle - React, Tailwind, and code Playground

HTML

<div class="result"></div>  
<div class="tAdd">+</div>

CSS

.tAdd {
    margin-left: 50px;
    cursor: pointer;
    background: #9a9a9a;
    padding: 2px 0px 2px 10px;
    position: absolute;
    top: 6px;
    color: white;
    width: 20px;
}

JavaScript

(function(){
	function increment() {
    let result = document.querySelector(".result");
    let step = 200;
    let currency = " р.";
    let value = step;

    result.dataset.value = (!result.dataset.value) ? step : parseInt(result.dataset.value) + step;
    result.innerHTML = result.dataset.value + currency;
  }
  
  document.querySelector(".tAdd").onclick = function() {
  	increment();
  }
  
})();