I have been to Barcelona just last Christmas... And I have used
http://en.venere.com/hotels_barcelona/ to book accomundation... They have hotel ranging from EUR40~100...
And with Airport just minutes by bus from Barcelona city, I would suggest you to find a hotel room in the city rather than around the airport... As there would be more option and cheaper as well in the city... Personally I have used Hotel Coronado on my last visit which is around 20minutes walk from the nearest Aeroport Bus station at Placa Espanya...