Lawrence has an issue with backing up his four computer's media files. Leo advises going with network attached storage that all four computers can access, and then back that up. Most NAS servers have software which will work with a variety of off-site cloud backup services like Carbonite.
Lawrence can get a NAS server, put it in a closet, and have it set up to backup automatically. Synology is a great one that Leo likes. Netgear's ReadyNAS is another option. He could also roll his own and create one using FreeNAS, an open source NAS utility. That chatroom says that he can get a Seagate 5TB External USB 3.0 hard drive with enclosure for under $129.