Catalog Price Rules, how to make them apply to tier prices?

Question

so say ive got products with different tier prices due to quantity purchased, is the any way to make a catalog price rule that for example takes 10% off all price tiers and not just the product price value ??

thanks.

Answer 1

No, you can't do that with a native Magento instance.
You would have to use shopping cart price rules for that, which are applied to the lowest of price, group price, tier price and special price.

Answer 2

Though an old thread i thaught i would help others that maybe looking for a code based answer.

This is not typically possible with magento, as the catalog price rules are very highly intergrated into the event structure for modifying final price, but this calculation is done before tiered price calculation. So unless the final price is less than the tier price the tier price will always be default.

In order to do this you will need to write a module and overwrite Mage_Catalog_Model_Product_Type_Price and look at

protected function _applyTierPrice($product, $qty, $finalPrice)
{
    if (is_null($qty)) {
        return $finalPrice;
    }

    $tierPrice  = $product->getTierPrice($qty);
    if (is_numeric($tierPrice)) {
        $finalPrice = min($finalPrice, $tierPrice);
    }
    return $finalPrice;
}

You can do your own method for proccessing the rule here. Please refer to Mage_CatalogRule_Model_Rule you will find the method you need to run.

Im purposely not giveing you the exact answer because how do you learn without looking into magento's depths.