You could try and generate the
Click Performance Report and get the corresponding
CampaignId of the GCLID. You can then filter the
Campaign Performance Report using the CampaignId and use the
CostPerConversion field to get average cost per converted click. There is currently no way to get specific click cost using GCLID via the AdWords API. I would also recommend that you follow our
blog for any updates or announcements regarding this feature.