Please excuse my ignorance of European ways, but is it possible, (and, mostly, cost-efficient) to book a flight from Santiago de Compostela to Barcelona same day? In all honesty, I have no clue when I will arrive in Santiago, and don't want to chance an online purchase of air tickets. In the US, any same day flight price would be completely over my head (pun intended ) and a stand by ticket at that. Please educate me! Thanks!