Get cheapest active product from given category.

getCheapestProductFromCategory.php

  <?php
    class Product {
    public function getCheapestProduct() {
        $data = Mage::getModel("catalog/product")->getCollection()
        ->addAttributeToSelect(Mage::getSingleton("catalog/config")->getProductAttributes())
        ->addAttributeToFilter('offer', Mage_MultiVendor_Model_Offer::STATE_ACTIVE)
        ->addCategoryFilter($this->getCategory())
        ->setPage(1, 1)
        ->addMinimalPrice()
        ->addFinalPrice()
        ->addTaxPercents()
        ->load()
        ->getFirstItem();
        
        return $data;
    }
    }