Play.com have the BlackBerry 8800 on Sim Free pay as you go (unlocked to any network) for £169.99. I think this is a good price considering that it isn't locked.
As stylish as it is powerful, the BlackBerry 8800 smartphone is designed to let you do your best work from wherever you choose. It gives you phone, email, organizer, web browsing and instant messaging. And then it goes a step further, providing GPS for enhanced access to location-based applications and services, including the pre-loaded BlackBerry Maps application. A media player for your video clips and music. Expandable memory to ensure you've got the room you need for your media files. And a high-capacity battery to allow you to make the most of it all.