WakeWorld - Back-up Solutions

I have been struggling with the right back-up solution for all of my computers at home. Because I am running both Windows, Mac and IOS devices there doesn't seem to be a logical solution. I would love to utilize Time Machine because it backs up all systems settings and files on a regular schedule but the only way that seems to work is with a very expensive Time Capsule.

Right now - I back up my core files (music, photos, files and video) over FTP (Filezilla) to my parents house in Seattle. I haven't tried to use Filezilla on my Mac but I understand it is possible. The downside is that I need to upgrade my NAS at my parents house because we are running out of room. The other downside is that it only does file replication not system replication and it is relatively random in terms of how often I actually get it done. The good thing is I am safe incase of floods, fire, etc.

I was thinking about buying a Time Capsule but I don't need another wifi router and the cost of a 3TB Time Capsule is like $500. Time Machine will work on my Windows machine but it has to be local which would be bad if I had a fire, flood, etc.

There seems to be some hacks for FTPing to a distributed network to a Time Capsule but that is getting beyond my area of expertise.

What are you doing for a back-up? Any recommendations that I am missing? No the cloud as it stands is not an option from Apple or Amazon because they are selective about which kind of files you can back-up at this point in their evolution. I would rather stay away from a subscription model for cost reasons if possible.