I used to have backup systems, but the only instance where it truly made any sense was my 2 PS2s, where one played blue discs but not PS1 games while the other was the other way around. I think a lot of it is paranoid thinking, worrying about things that haven't happened yet. Systems are easy to replace, especially with all of the after market ones coming out all the time. Having multiples makes you feel 'in control', which certainly has a psychological component, but if it's obsessive is another story. FYI, I didn't regret selling my duplicates at all.