Using Dropbox as a bridge to your local hard drive

Hi guys
I am developing a desktop app that automates moving files from one folder to another it actually keep watching the source folder and when new files appear it move them to other destination, I am trying to solve a problem I had before when I was travelling to HongKong, I was making videos then I run out of disk space and I could not save somewhere else, at the same time I had large disks at home but they are at home (duh) in London, I have a free Dropbox account and I don't want to pay monthly for it, it gets very expensive very quickly.
So my idea is to have this app open on my computer at home where it keeps watching a folder inside my dropbox (or google drive etc...) and whenever there are new files it moves them to my hard drive, me from the other side I will just dump files and watch them disappear, so basically I would be using dropbox as a bridge to my hard drive, there are limitations to this like I cant exceed disk limit I have on dropbox, but I think it could be useful for some people.
I would like to know your opinion

Thank you