<?php 

    global $product;

    $stock_status = $product->get_stock_status();
    $stock_quantity = $product->get_stock_quantity();
    $price = $product->get_price();

    if ($stock_status === 'outofstock' || $product->is_type('variable') || empty($price)) {
        return;
    }

    echo '<div class="quantity">';
    echo '<input type="button" value="-" class="minus">';
    echo '<input type="number" step="1" min="1" name="quantity" value="1" class="input-text qty text" size="4" max="' . $stock_quantity . '" data-max-stock="' . $stock_quantity . '">';
    echo '<input type="button" value="+" class="plus">';
    echo '</div>';

?>