Hello everybody! I am a louis vuitton newby so I apologize if my question is idiotic. I am currently eyeing the speedy 30 with the shoulder strap. However, I am also trying to justify the extra 300$+ for the shoulder strap. I read somewhere that you could buy a shoulder strap separately for the regular speedy 30. Is this true? Is this a better option? If not, is the extra money worth it for the strap? Thanks everybody!