My backup set is on 3 sets. If one DVD gets a scratch or fails, I get 2 more tries. That being said, the media, under proper storage should work for over 10 years.
But what they didn't tell you is that most PC DVD drives begin to have issues at 2 years. The poor owners start to think their DVDR or such media went bad.
Hope this helps,
These are reasonable priced at shops near me but i cannot afford to lose the information once burnt. Which of these are of higher quality and will last longer.
Both say they are made in Taiwan.
Using a Plextor PX-716A to burn.