I was in Sainsburys doing regular grocery shop and noticed them, thought I'd be helpful and let ppl know, as normally when I need discs I buy from play.com, where Verbatim 100 DVDs are about £18.
I'd rather use Verbatim than unbranded discs. Sometimes unbranded work fine, sometimes they don't, I guess it depends what you're burning whether you want to risk it or not.
The one I was in today is a 5-10 min walk, if you're interested