Roy, I don't know anything about retail trading in England, but retail traders here in Belgium are bound by law to sell their goods at 2.2 times the wholesale price. Say that they buy-in at £1 they sell at £2.20, they may give a discount but are still taxed on £1.20 profit. Twice a year they can hold a sale, Winter and Summer sale, sell at -50%, £1.1 that's 10p frofit that they get taxed on. What I'm trying to say is that they may be selling those Tom Toms at a loss to to get rid of stock before a new model is released.
I agree that England has become a 'rip-off' country, everyone here that visits England these days complains about the price of things and will think twice about a second visit.