$('.basket-page2__main-item-item2-number').on('click', function(evt) {
var elem = evt.target;
var container = evt.currentTarget;
var input = container.getElementsByClassName('number-input')[0];
var sum = container.getElementsByClassName('sum')[0];
var count = parseInt(input.getAttribute('data-count'), 10);
var price = parseInt(input.getAttribute('data-price'), 10);
if (elem.classList.contains('fa-minus')) {
count = count == 1 ? count : (count - 1);
} else if (elem.classList.contains('fa-plus')){
count += 1;
}
input.value = count;
sum.innerHTML = price * count + " Р";
input.setAttribute('data-count', count);
});