American Airlines, Delta, and SkyTeam partners have round-trip flights from Austin (AUS) to Barcelona or Madrid (BCN/MAD) for $441-$525 with a connection. Flights November to May. Holiday blackouts apply. 8-day minimum stay required. Flight may operate as a KLM code-share.
Note: Carry-on bag is allowed for free, but checked bags will cost about +$60 each-way. Upgrades into “Regular Economy”, which allows for a “free” checked-bag are available for +$45 each-way.