Displaying Magento tier prices instead of main prices for groups

I've been tackling a particularly annoying problem with Magento, in that I've got specific pricing by groups, imported from another database, but while it'd show the tiered prices in a box, it'd always show RRP on the front page. Fixing it to show the first tier price for quantity 1 on the product page was easy enough (using $this->getTierPrices()), but the tier prices simply aren't present on the grid / listing page, and it really didn't want to let me retrieve them by group either.

So, in case it helps anyone else out at a later date, this is how I got around it, displaying tier prices instead of the main prices on the listing page as well as the main product display page. (Tested on Magento 1.4.1.1, later versions may vary.)

Around line 58, after the following

getPrice($_product, $_product->getPrice()) ?>
getPrice($_product, $_product->getPrice(), $_simplePricesTax) ?>
getPrice($_product, $_product->getFinalPrice()) ?>
getPrice($_product, $_product->getFinalPrice(), true) ?>

add:
getTierPrices();
if (empty($_tierPrices) && $this->helper('customer')->isLoggedIn()) { // No tier prices found, attempt manual retrieval if customer logged in
$resource = Mage::getSingleton('core/resource');
$query = 'SELECT qty AS price_qty,value AS price FROM '.$resource->getTableName('catalog/product').'_tier_price WHERE entity_id = '.$_id.' AND qty = 1 AND customer_group_id = '.Mage::getSingleton('customer/session')->getCustomerGroupId();
$_tierPrices = $resource->getConnection('core_read')->fetchAll($query);
}
if (!empty($_tierPrices)) {
foreach($_tierPrices AS $tierPrice) {
if ($tierPrice['price_qty'] != 1) continue;
$_price = $tierPrice['price'];
$_finalPrice = $this->helper('tax')->getPrice($_product, $tierPrice['price']);
$_finalPriceInclTax = $this->helper('tax')->getPrice($_product, $tierPrice['price'], true);
break;
}
} ?>


I also had to alter the following line lower down to avoid displaying "as low as" for items that didn't have lower than the first tier price:

From:
getDisplayMinimalPrice() && $_minimalPriceValue && $_minimalPriceValue < $_product->getFinalPrice()): ?>

To:
getDisplayMinimalPrice() && $_minimalPriceValue && $_minimalPriceValue < $_finalPrice): ?>

Hope this helps someone out, as it had me scratching my head for a bit, and the online documentation I found wasn't brilliant. In the end the most efficient way seemed to be to rip it straight out of the database. Credit to the stack overflow question that pointed me in the right direction to run the query, modified to select only the customer logged in group and quantity 1 for efficiency.