diff -r 89cb89a1e805 -r ba9aa74de595 commerce_price_table.module
--- a/commerce_price_table.module	Sat Jan 19 20:24:04 2013 +0100
+++ b/commerce_price_table.module	Sat Jan 19 20:41:19 2013 +0100
@@ -457,18 +457,7 @@
 /**
  * Get the price for the min qty possible in a product.
  */
-function commerce_price_table_get_amount_qty($product, $quantity = 1) {
-  $items = array();
-  $product_wrapper = entity_metadata_wrapper('commerce_product', $product);
-  $fields = commerce_info_fields('commerce_price_table', 'commerce_product');
-  foreach ($fields as $field) {
-    if (!empty($product->{$field['field_name']})) {
-      foreach ($product_wrapper->{$field['field_name']}->value() as $item) {
-        $items[] = $item;
-      }
-    }
-  }
-
+function commerce_price_table_get_amount_qty($product, $quantity = 1, $items = array()) {
   // Sort the items by quantity and return the matching one.
   $result = false;
   uasort($items, 'commerce_price_table_sort_by_qty');
diff -r 89cb89a1e805 -r ba9aa74de595 commerce_price_table.rules.inc
--- a/commerce_price_table.rules.inc	Sat Jan 19 20:24:04 2013 +0100
+++ b/commerce_price_table.rules.inc	Sat Jan 19 20:41:19 2013 +0100
@@ -17,6 +17,10 @@
         'label' => t('Quantity'),
         'type' => 'decimal',
       ),
+      'price_table' => array(
+        'label' => t('Price table'),
+        'type' => 'list<commerce_price_table>',
+      ),
     ),
     'group' => t('Commerce price table'),
   );
@@ -24,13 +28,13 @@
   return $actions;
 }
 
-function commerce_price_table_set_price($line_item, $quantity) {
+function commerce_price_table_set_price($line_item, $quantity, $price_table) {
   // If the line item contains a product, we set the price according to the
   // quantity.
   if (commerce_line_items_quantity(array($line_item), commerce_product_line_item_types())) {
     $line_item_wrapper = entity_metadata_wrapper('commerce_line_item', $line_item);
     $product = commerce_product_load($line_item_wrapper->commerce_product->product_id->value());
-    $item = commerce_price_table_get_amount_qty($product, $quantity);
+    $item = commerce_price_table_get_amount_qty($product, $quantity, $price_table);
     if (!empty($item)) {
       // Empty the price components to recalculate them.
       $line_item->commerce_unit_price[LANGUAGE_NONE][0]['data']['components'] = array();
diff -r 89cb89a1e805 -r ba9aa74de595 commerce_price_table.rules_defaults.inc
--- a/commerce_price_table.rules_defaults.inc	Sat Jan 19 20:24:04 2013 +0100
+++ b/commerce_price_table.rules_defaults.inc	Sat Jan 19 20:41:19 2013 +0100
@@ -20,9 +20,18 @@
 
   $rule
     ->event('commerce_product_calculate_sell_price')
+    ->condition('entity_has_field', array(
+      'entity:select' => 'commerce-line-item',
+      'field' => 'commerce_product',
+    ))
+    ->condition('entity_has_field', array(
+      'entity:select' => 'commerce-line-item:commerce-product',
+      'field' => 'field_price_table',
+    ))
     ->action('commerce_price_table_set_price', array(
       'commerce_line_item:select' => 'commerce-line-item',
       'quantity:select' => 'commerce-line-item:quantity',
+      'price_table:select' => 'commerce-line-item:commerce-product:field-price-table',
     ));
 
   $rule->weight = -10;