You could always use something like Dropbox. If you are willing to pay for an external, you can get quite a bit of storage from Dropbox. As of now, you can get 50 GBs of storage for 99 a year. I'd also assume that's on top of your free space which you can get with referrals.
From Dropbox:
"Each friend you refer to Dropbox yields 500 MB of free space. In total, you can get up to 16 GB for Dropbox Basic accounts (for a total of 18 GB plus whatever other free space you've earned), and 32 GB for Dropbox Pro accounts (in addition to the amount you paid for already)."