u should be able to get an official tomtom pack with the gps receiver and the software for under £150
Pre-installed Safety Cameras database: The most up-to-date available list of safety cameras is pre-installed on your NAVIGATOR. Click here for more information.
http://www.tomtom.com/products/features.php?ID=276&Category=2&Lid=1
That's not a bad price for everything. Are you planning on using the PDA for more than TomTom? If not then you'd be better off buying the TomTom One.