Передача value из input в input [требует правки]

document.querySelector('.products').onclick = function(e) { 
  if(e.target.classList.contains('product__order')) { 
  var priceValue = e.target 
    .closest('.product') 
    .querySelector('.product__price') 
    .innerHTML; 
 
    document.querySelector('.form input').value = priceValue; 
    document.querySelector('.form').classList.add('form--open') 
  } 
}

.product { 
  width: 100px; 
  height: 100px; 
  padding: 10px; 
  border: 1px solid; 
  display: inline-block; 
  vertical-align: top; 
} 
 
.product__price { 
  font-weight: bold; 
  margin-bottom: 1em; 
} 
 
.form { 
  display: none; 
  width: 100px; 
  height: 100px; 
  box-shadow: 0 0 10px rgba(0, 0, 0, 0.5); 
  position: fixed; 
  left: 0; 
  top: 0; 
  right: 0; 
  bottom: 0; 
  margin: auto; 
  padding: 10px; 
} 
 
.form--open { 
  display: table; 
}

<div class=products> 
  <div class=product> 
    <div class=product__price>$1000.50</div> 
    <button class=product__order>Order</button> 
  </div> 
  <div class=product> 
    <div class=product__price>$1100.50</div> 
    <button class=product__order>Order</button> 
  </div> 
  <div class=product> 
    <div class=product__price>$1200.50</div> 
    <button class=product__order>Order</button> 
  </div> 
  <div class=product> 
    <div class=product__price>$1300.50</div> 
    <button class=product__order>Order</button> 
  </div> 
</div> 
 
<div class=form> 
  <form> 
    <input type=text /> 
  </form> 
</div>