I recently spent 7 glorious days in sunny and warm Barcelona helping my 18 year old niece settle into her new apartment having just started university there . I travelled with my mother and whilst my brother offered the possibility of top class rooms at the Hotel Arts my mum preferred the idea of an apartment that would give us more freedom and would make us feel more integrated with Barcelona life . My family often hire apartments and houses instead of hotel rooms . The apartment we hired was near the Tetuan metro station and only maybe 15 minutes walk max to Placa Catalunya ... Incredibly central . 3 bedrooms .. very modern inside , free wi-fi ... I think the apartment was about 125 square metres .. with a nice spacious balcony at the back . It cost ( for 6 nights ) about 850 Euros . Considering it would easily sleep 6 people .. approx 140 euros a night has to be a great bargain . The company we used offers apartments in many other areas of Spain and Europe . They were very good with us and very friendly ... so , just on this one occasion , I'd like to recommend : http://www.friendlyrentals.com/
If you're in Spain your contact will be with a local rep . So any problems would be directly dealt with . Our rep was a lovely Slovenian lady that spoke great Spanish and perfect English .
The apartment we hired was : http://www.friendlyrentals.com/en/apartments/barcelona/apartment-1055-1.htm