I've noticed that products in UK stores are priced at about the same number of British pounds as we pay for the product in U.S. dollars. Considering the exchange rate, that makes the same product about 63% more expensive. Aside from food, fuel and lodging, I limit my purchases to items that I can't get in the U.S. Welsh language books and music in particular.
The U.S. consumer tends to be a savvy shopper in a sea of competitive retailers. In general, the party with the lowest price earns the business. Patience is a virtue. No tax, free shipping and a big discount often comes at the expense a of delayed shipping date.
I'll pay a higher price only if it means I can gain a competitive advantage by having the item immediately.
In fact, one of the biggest problems the UK experiences is Brits buying goods from continental Europe at VASTLY lower prices than you can get in the UK, even after import duty taxes are imposed when the UK citizen brings the goods back into the country. In fact, in the Calais area (the southern end of the Channel Tunnel and a major shipping port for cross-channel shipping to the UK) there are many French stores that specialize in selling food products produced in continental Europe specifically to UK citizens.