I think you want:
<?php
$rsItemGroupOptions = new WA_MySQLi_RS("rsItemGroupOptions",$ecartdb,0);
$rsItemGroupOptions->setQuery("SELECT * FROM options WHERE OptionGroupID = ? ORDER BY OptionPrice, OptionName");
$rsItemGroupOptions->bindParam("s", "".(isset($_GET['OptionGroupID'])?$_GET['OptionGroupID']:"") ."", "-1"); //colname
$rsItemGroupOptions->execute();
$lowPrice = $rsItemGroupOptions->getColumnVal("OptionPrice");
?>