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OneDrive is much better than the Dropbox, Onedrive give you Unlimited space with Office 365 for $70 year
FYI
I had asked one of the dropbox agents if i want to cancel a monthly or yearly upgrading plan,, the answer was:
If you downgrade to the free plan, your storage will change to a 2GB limit at the end of your current billing cycle. What will happen is if you are over that limit, you simply won't be able to upload any more files into your Dropbox account, and your account will also stop syncing. But your files will remain in your account.
means you lose the space and money, you only won the saved files will not be deleted