i think thats the same price they are in Halfords (when i was looking at them for my car the other day) so going on the fact that generally halfords are expensive i'd say no.
Just visit your local motor factors rather than buying gimmicks. 4 plugs for mine (NGK-R) cost me £6.20.
Damn, was just about to post about NGK's. I bought 4 for my car. Cost me just over a tenner including p+p.