I got this letter in the post asking me to re-join sky and offered half price sky for 12 months.. So this deal may be only for rejoining customers..
It works out to be £ 9.50 per month
And you can add more packs (optional) at 50p per month each.
Not sure if sky honours the deal for new /existing customers but worth a try
You need to call 08442 410 646
and quote 'SKYTV5'