We use Synology NAS at work. Very capable, but pricey and way more complex to setup and manage. WDD and Buffalo do a much better job with their NAS software.
Ours is more complex than average for sure.
But the WDD stuff is actually really simple
1. Buy a drive with the capacity you need.
2...
This. Have WD dual drives in a raid 0 configuration 4tb ea. Plus cloud backup. Both safe and can access from anywhere via the web. We now have 3 I'm the house, master with all shared stuff one for my wife and one for my son. Those 2 backup to the master which backs up to cloud. Easy to setup and...