American Airlines and Oneworld partner airlines Iberia and British Airways have several cities across Portugal and Spain priced from $381 to $398 round trip. Switzerland and Italy are priced in low to mid-$400s. Delta/SkyTeam compete on several of these routes with lower fares to some cities like Malaga and Seville, but about $10 to $20 more for most cities. Star Alliance also has some competitive fares.
Departure Dates: January to May 2017; Aug 23 – October 2017
Google Flights March 2-9 Boston to Portugal/Spain with Oneworld Alliance
Portugal
Lisbon $528 (Ryanair flights between Porto and Lisbon are $14 each way).
Spain
Malaga $434 Aer Lingus (Air France $400)
Iberia Airlines Boston BOS – Madrid MAD – Tenerife, Canary Islands, Spain TFN – MAD – BOS
$392.48 round trip Sun Mar 5 – Sun Mar 12
Loyalty Traveler curated Airfare Deals and Google Flights and Kayak Explore tutorials.