Используйте сервис ReportDefinitionService. Пример на php:
https://developers.google.com/adwords/api/docs/sam...
Поле "Cost" - расход по кампаниям.
<?
function DownloadCriteriaReportExample(AdWordsUser $user, $id, $start,$end) {
$user->LoadService('ReportDefinitionService', 'v201603');
$selector = new Selector();
$selector->fields = array('CampaignId','CampaignName', 'Impressions', 'Clicks','Ctr', 'Cost', 'StartDate');
$reportDefinition = new ReportDefinition();
$reportDefinition->selector = $selector;
$reportDefinition->reportName = 'Criteria performance report #' . uniqid();
$reportDefinition->dateRangeType = 'CUSTOM_DATE';
$startDate = $start;
$endDate = $end;
$selector->dateRange = new DateRange($startDate, $endDate);
$reportDefinition->selector = $selector;
$reportDefinition->reportType = 'CAMPAIGN_PERFORMANCE_REPORT';
$reportDefinition->downloadFormat = 'CSV';
// $reportDefinition->includeZeroImpressions = false;
$options = array('version' => 'v201603');
$filePath = dirname(__FILE__).'/upload/'.$id.'.csv';
ReportUtils::DownloadReport($reportDefinition, $filePath, $user, $options);
}