I use a HP microserver as my NAS with 3 disk RAIDz as primary storage for all active editing and all are backed up weekly to a separate HDD. I still do not have an off site storage which I will want to look into if my internet didn't sux so much. Running that system close to 10 years already and so far so good touch wood.

For us regular photographer a home NAS with backups is good enough. At the end of the day the sky is the limit in terms of how much you want to spend for it. Online cloud... Well you need to have solid internet unfortunately and have to pay.