I see that Sky currently have an on-line exclusive Flash Sale for new customers or those that left Sky over twelve months ago.
Sky TV bundles - the latest in Digital TV, 3D TV and Movies on Demand
Sky TV

Flash Sale – get 33% off selected Sky TV Bundles.
Join online today and you’ll also get a £25 reward. Or, get a £50 reward when you add Sky Broadband.
Note: This does not include the £20/month Original Package.
33% off Sky TV offer: subject to status. Upfront payment may be required. New Sky TV customers receive 33% off the standard monthly price of the Variety, Family, Movies, Sports or Complete Bundle for 12 months (then standard pricing). 12 month minimum subscription. After 12 months you'll pay the standard price of your Sky TV, unless you give at least 31 days’ cancellation notice. Offer not available with any other Sky TV offer. £10 set-up fee applies. Prices may go up during your contract. Offer ends 18 February 2016. Choice of reward: New Sky TV customers only. Sky TV £20-£75.75 pm. Set up fees apply. 12 month minimum subscriptions. Choice of a £25 Tesco in store voucher, M&S e-Voucher or Prepaid MasterCard®. when taking any Sky TV Bundle. Choice of reward when taking Sky TV and Sky Broadband Unlimited, Sky Fibre or Sky Fibre Unlimited: £50 Choice of Tesco in store voucher, M&S e-Voucher or Prepaid MasterCard®. Sky Line Rental at £17.40 a month applies. £6.95 router delivery charge. Broadband customers must take Sky Talk (available from £0 a month). You must claim your reward online at www.sky.com/claim within 90 days of your service being activated. To receive the Tesco in store voucher or M&S e-Voucher you need a valid email address and the ability to print. Tesco in store voucher not redeemable online. Prepaid MasterCard® can be used where MasterCard® is accepted, except for gambling, cash withdrawals, currency, cashback or at petrol station. Not available with any other Sky TV offer. M&S, Tesco, MasterCard® and further terms apply. One reward per household. After 12 months you'll pay the standard price of your Sky TV and Broadband package, unless you give at least 31 days’ cancellation notice. Offer not available with any other Sky TV offer. Prices may go up during your contract. Offer ends 18 February 2016.