As a linux user I use, Resilio Sync (formely Bittorrent Sync) with a VPS on serverhub.com . I pay $15 a year per 125 GB. It might not be as good as dropbox but

As a linux user I use, Resilio Sync (formely Bittorrent Sync) with a VPS on serverhub.com . I pay $15 a year per 125 GB. It might not be as good as dropbox but the price worth it. I can even store the files encrypted. (I am not affiliated with neither Resilio sync or serverhub, just a happy user)