Was just in my local PC world (Trafford) and they had the BT VP1000 home alarm pack for £14.97 in stock clearance, they had 8 left. I already have one and its done a good job for 18 months, been very reliable, I bought this pack as a backup unit, its much cheaper than buying the extra sensors and good to have a backup if the main unit fails.
You get a 3 month free subscription to the BT monitoring service, after that its £5 per month, I cancelled after the free trial, the alarm still works fine, just means you don't get a phone call/txt/email when the alarm is triggerred.
There are plenty of extra types of sensors you can buy, such as smoke/flood alarms, so its an easy to fit, reliable unit which gives extra peace of mind, the internal alarm is *VERY* loud and would put any burglar off when triggerred.
The only thing that does not come with this pack is a dummy bell for outside your house, my original pack I got 18 months ago came with one, which is useful, I'm sure there on ebay for a couple of £'s.
I'd advise anyone without an alarm to buy this unit, its easy to install, wireless and very reliable, I've had no false alarms (only triggerred when I've forgot to disarm it and triggerred the PIR motion sensors !)
I've checked online at PC World and cannot find the BT VP1000 listed, I've not checked any other PC world stores, all I can say is Trafford definitely had 8 packs left after I bought mine today, I presume its a stock clearance accross the group, so I would recommend calling your local PC world to check stock/price before visiting.
I've found the sensors on the PC World website, one movement PIR (you get 2 in this pack) is listed at £29.35 + delivery !!!
BTshop has this online for £176.16, though you can pick these units up for about £50 from e-bay etc, here's the URL for info :http://www.shop.bt.com/productview.aspx?Quicklinx=4K43&SearchType=1&SearchTerms=vp1000&PageMode=3&SearchKey=All&SearchMode=All&NavigationKey=0
Official Info :
The BT Home Monitor VP1000 is an intelligent house alarm system that alerts you to intruders wherever you are in the UK, via e-mail, text message or a fixed-line telephone call. You can also raise an alarm if you come under personal attack. The VP1000 is the complete Home Monitoring and Alarm System, giving you control and the ability to manage your system through a personal password-protected online account. This is a self install unit which uses wireless sensors.
Supports up to 28 sensors
Alerts designated contacts via phone, email, SMS
Monitor the status of your home, via Internet
The kit contains
VP1000 Home Monitoring System
Keyfob - 1 unit
Magnetic Detector - 1 unit
Movement Detectors - 2 units
This is subject to a subscription to a monitoring service incurring a separate monthly fee. The BT Home Monitor VP1000 comes with first 3 months monitoring included in the price. After this time, monitoring is charged at a monthly fee of £5.00. International numbers cannot be entered as a fixed line phone contact, please ensure you have entered a mobile and/or e-mail account to receive text or email alerts when abroad.
System requires power-supply and connection to a telephone line.