Why is the Charlie and the Chocolate Factory movie set in england, but using american currency and lingo?

Despite the fact that the story (originaly written by Rohd dahl) is english, nearly every actor (from extras to main characters) speaks with an enligsh accent and the movie is set in london, the currency in the movie is american dollars and cents and there are lines that use american lingo, such as "candy" and "band aid". Just what the hell is going on? is it america or england!Why is the Charlie and the Chocolate Factory movie set in england, but using american currency and lingo?A lot of American movies are produced in England, thus many of the actors and extras are locals from that area. If you've ever seen 'Superman 2 (as one example) you probally noticed that the scene when Zod and gang are in the desert town that the boy and the sheriff all have English accents. This is the same way in many movies made there and many were...lol :)Why is the Charlie and the Chocolate Factory movie set in england, but using american currency and lingo?Hmmm, maybe the realistic oompah loompas made me forget about the accent. HELLO??????McFly????