In my opinion, anything over a 3 year guarantee is just for marketing.
For example, based on an e-mail just over 9 years ago, I bought a 3.5" 320GB IDE hard disk for â‚¬163, which was quite a lot at the time. If I still had that hard disk and it failed today under guarantee, I could not imagine wanting to go through the bother of replacing it under warranty.
As for a quick check about five years ago, I bought an OCZ Agility 60GB in September 2009 for â‚¬181. If that was still under warranty, I’d probably wonder what’s the point in replacing such a low capacity SSD.