www.farecompare.com/flyertalk

Enter the city you want to fly from and check off Europe. From my town, barcelona and madrid always come up fairly cheap per mile. Just for reference, the very cheapest fares run 0.04 cpm and you would be lucky to pay 0.06. I've seen estimates of 0.15 cpm for airline breakeven on costs. I'm not sure if thats including labor, fuel, lease/depreciation, overhead, ceo bonus ...