<?php
error_reporting(E_ALL | E_STRICT);
ini_set('display_errors', 1);
ini_set('max_execution_time', 0);
ini_set("memory_limit","-1");
require_once('app/Mage.php');
umask(0);

Mage::app()->setCurrentStore(Mage::getModel('core/store')->load(Mage_Core_Model_App::ADMIN_STORE_ID));

$products=Mage::getModel('catalog/product')->getCollection()->addAttributeToSelect('price');
$data=array();
foreach ($products as $product) {
  $p=array('sku'=>$product->getSku(),
    'msrp'=>$product->getPrice(),
    'price'=>$product->getPrice()*1.2
    );
  $data[]=$p;
}

$import = Mage::getModel('fastsimpleimport/import');
try {
    echo $import->processProductImport($data);
} catch (Exception $e) {
    print_r($import->getErrorMessages());