China Southern has another cheap European fare, this time to Barcelona in May/June for $977 return. This is the cheapest ever Barcelona fare by $300 on Cheapies. The catch is there is a 17 hour layover in Guangzhou however you'll get a free hotel courtesy of China Southern. There's also another shortish stop in Amsterdam on the way.
Find the cheap days to fly on Google Flights then plug them into Skyscanner.