That is ten quid more than the price of AAA new release games in Australia.
Consider yourself lucky that you haven't been getting ripped off for years. Sure, this might be quite expensive, but all Australians have been buying games at around this price for quite some time. Even when our exchange rate was nearly identical to Americans we still paid twice the price.
Want to know something England, you're going to buy those games if they cost 100 pound. If they stretch up to 150, you're still going to buy them. We still do. Rock Band was an insane price, like $350+ dollars (or something similar) and it sold like hot cakes. I don't mean to be the bearer of bad news, but this is a likely outcome and a few months after, you're not going to mind paying 70 or higher for a game.
I still can't believe that people are throwing a fit over the 55 pound price tag on MW2. We pay 60.1668 pounds for our games and have been doing so for the past, what, four years? Maybe three?