Got a Macbook Pro coming next week 
Will be going from almost 2GB of storage on my current laptop to just 256GB, and was contemplating using an 128GB SD card to store my Itunes library. Is this practical? Would probably be paying a premium for a 'pro' level card.
Ideally I'd like the card to remain in the machine 24/7 so that probably rules out a thumb drive.
Any other solutions for increasing storage without going the external hard drive route?

Will be going from almost 2GB of storage on my current laptop to just 256GB, and was contemplating using an 128GB SD card to store my Itunes library. Is this practical? Would probably be paying a premium for a 'pro' level card.
Ideally I'd like the card to remain in the machine 24/7 so that probably rules out a thumb drive.
Any other solutions for increasing storage without going the external hard drive route?