White (I think, as seen in the paper) usually costs £34.99 & £2.95 postage). There is a free Standby Saver extension (6 plug) for British Gas customers, both pics in post 8).
The monitor is for anyone, but only British Gas Customers can receive the Standby Saver.
Obviously it will be a form to fill in, but they say that they'll pay the postage. Probably worth buying the paper to get the monitor even if the paper goes straight in the recycling bin:)
PS. Don't use "Go To Deal" as it is in the paper only :)