When creating a webapplication or API it’s important to test how well your site will work under heavy load, it’s easier to prevent any problems beforehand, compared to doing it when you find out your server is getting swamped with requests.
If you are having problems with products not being saleable in magento, make sure you add the price attribute to the select, otherwise it will always return false!
$collection = Mage::getModel('catalog/product')->getCollection();
$collection->addAttributeToSelect('name')
->addAttributeToSelect('image')
->addAttributeToSelect('price')
->addAttributeToSelect('url_path')
->addAttributeToSelect('status')
->addUrlRewrite();