I found cheaper tickets to Manchester England with a stop in Dublin cheaper than a flight to Dublin. So I purchased the flight to Manchester and got off in Dublin. (No checked luggage)
I often purchase my tickets at the foreign affiliated website rather than the US airlines. For example, I purchase tickets to Asia on Korean Air and end up on Delta Flights as they are affiliated.
I puchase my Delta tickets to Europe on the KLM website. They have been much cheaper and I’m on the same plane.
Back before they folded, I bought Air Berlin tickets to Germany instead of American Airlines. Rode on and AA plane and got AA frequent flyer mileage. Saved a few bucks - not an economically significant amount but enough to feel I’d put one over on the man.
Do you know if you can use Delta’s Freqent Flier miles on KLM? I know it depends on the flight but I’m wondering if I could do better using my miles that way.
Booking on foreign sites/travel agents also works for hotels, I was able yo get two cheap fares from Paris to Madrid on a Columbian airliner as well as two low priced/centrally located rooms in Madrid by using a Spanish booking company.
This was much lower than any US site.