SD/Micro SD cards are really cheap. I got a 32 GB one by SanDisk for my phone and it only costed me £15 (about $22).
JOEBOT, lovingly handmade by MattSuda - I'm not the only sexy rock star, there are plenty of others that are happy to help you out. Just look for the star by their name. - I AM NOT AN EMPLOYEE OF SPOTIFY AB. I am just a thirteen year old child trying to help out. I am not paid to help or say any views of Spotify AB or any of it's affiliates, so the least that you could do is share some kudos, or, if I helped you out, mark my post as a solution. It makes me all fuzzy inside