When there are more than 3 people in your group you will save as the average apartment will cost less than the price of a double room in a hotel.
Often the 1-bedrrom apartments have 1 additional pull-out bed in the lounge area that will give you the option to have more people in the flat. The typical Barcelona apartment for rent costs between 80 to 120 €/night for the whole apartment.
The price you pay obviously depends on several factors including the location, and quality of the apartment and its desirability.
You will also be able to find apartments to rent in Barcelona locations that are difficult or too expensive to find a hotel e.g. the beach area (Barceloneta).
Here you have the list of our 1 bedroom apartments:
Penthouse 3 levels. Level I (35 sqm): Dining area with a fully equipped kitchen with all new appliances, table with 6 chairs, bathroom and a living space with TV, music and 2 wide confortables sofa-beds. The ceilings have been restored and they keep their wooden beams. Level II (35sqm): Double room with a modern bathroom (15 sqm) and private terrace with a dirning table and 6 chairs (10sqm). Level III (15sqm): Private solarium-terrace with a small table and modern deckchair for 4 people. Great views to the city and sun ALL day long. Important: 5th floor without lift.