Newbie questions

Although that’s true, a node can be recovered even if it loses all of its databases. If this happens and if you react soon enough to fix the issue, you may miss some days of revenues but that’s about it.
Whereas it will get disqualified for good (that is banned from the network) if it loses a few percents of the data it is storing so that’s definitely the most important thing: integrity of stored files.

@o1eal: On another note, you may want to have a look at this estimator made by one experienced SNO, to have a rough idea on what ROI to expect (copy it in your own Google account and then fill in your numbers):