Wow, who knew? Thanks for the heads-up.The airlines know Europeans will not pay the same amount as Americans to visit their respective continents. Therefore, airfares originating in Europe are far less expensive—likely a reason that one-way tickets are not affordable.
Look at:
GVA - (EWR or DEN) vs. (EWR or DEN) - GVA Almost a 50-100% markup. Maybe you can play around with spoofing and VPNs