PHL is also my home airport and we can never find flights to Europe that are cheaper than EWR or JFK. We went on a cruise last fall that left from AMS and ended in Barcelona; we flew Aer Lingus from JFK via Dublin round-trip because it was $400 cheaper than flying directly from PHL. Saving $800 (minus parking, gas and tolls) and flying JFK was worth it to us. You are very lucky.