You can find the list of nearby hotels HERE. Hotels near APC are more expansive. There are options of hotels in the center of Paris in Quartier Latin, some of which have reasonable price. One can reach APC building from Quartier Latin by RER C or metro. From RER C station 'Saint-Michel Notre-Dame' 2 stops to 'Bibliotheque Francois Mitterrand' takes 5-10 minutes. Take the 'south' exit ('Grands Moulins') and walk another 5 minuts. APC building is on the picture below.