Dunno, but whatever you pay, be sure to factor in any monthly or annual
subscriptions when calculating cost of ownership.  Bear in mind that
most of the PDA based sat-nav systems, along with quite a few of the
stand-alone models will let you download 'points of interest' and you
can get the speed camera locations (updated monthly) free of charge if
you know where to look.

There's no way I'd consider a Road Angel at full price.  Not when you
can have the Tom-Tom Go 300 for less, which appears to do the same job
using the free camera database and gives you sat-nav to boot.  If you're
looking for a dedicated GPS speed camera 'detector' on the cheap,
Woolies are now selling one for (IIRC) around 80 quid.  The gizmo
doesn't look as well featured as even the first generation Road Angel,
and I don't know how the accuracy of the databases compares, but it must
be better than nowt for 80 quid.  Like Road Angel, they appear to be
expecting to make money in the long term by making you pay a
subscription to keep the data up to date.