RAID is not backup. Repeat that 50 times. This is one of the things I have to tell customers and potential customers dozens of times, and many still don't quite "get it". Oh well, at least you do
RAID = for *availability* purposes ONLY. Meaning, if a drive fails, your machine doesn't die. Just swap a drive out when it's convenient.
Backups = Business continuity. This actually protects your DATA in the event of a "anything" failure. Absolutely required no matter how small or large the business.
Remember, good backups are not "cheap". Meaning, either you're paying $$$ for them (PC, hosting, whatever), paying in time spent admin'ing them, or paying in the form of a bad solution that likely isn't protecting you very reliably.
Rant over!