<!DOCTYPE html>
<html>
<head>
<meta http-equiv="content-type" content="text/html; charset=utf-8" /><title>ГГ</title>
<style>
* {
margin:0;
padding: 0;
outline: none;
}
.container {
margin: 50px;
border: 1px solid red;
}
</style>
</head>
<body>
<form class="container">
<div class="vvod">Введите стоимость товара:</div>
<input type="text">
<div class="text">
<span class="cost">Стоимость товара</span>
<span class="cost-price"></span>
<span class="rubl">руб.</span>
</div>
<label for="sber">Сбер: <input type="radio" id="sber" name="cost"></label>
<label for="sber">Яндекс деньги: <input type="radio" id="yad" name="cost"></label>
<label for="sber">Терминал: <input type="radio" id="terminal" name="cost"></label>
</form>
<script>
var costPrice = document.querySelector('.cost-price');
var sber = document.querySelector('#sber');
var yad = document.querySelector('#yad');
var teminal = document.querySelector('#terminal');
var input = document.querySelector('input[type="text"]');
input.oninput = function(){
costPrice.innerHTML = input.value;
}
sber.onclick = function(){
costPrice.innerHTML = (input.value*1.03).toFixed(2);
}
yad.onclick = function(){
costPrice.innerHTML = (input.value*1.01).toFixed(2);
}
teminal.onclick = function(){
costPrice.innerHTML = (input.value).toFixed(2);
}
</script>
</body>
</html>