Amazon: £24.99
HMV: £24.99
Game: £24.99
(Remember that some places charge postage depending on what postal class you choose)
(These are UK-based prices when looking online)
As you can see, there seems to be a consistent price at the moment. These are, for the UK, pre-order deals with a saving of around £5.00, according to the websites. It's highly possible, therefore, that when the game is actually released, the game will go back up to being around £30. Depends on whether or not the deal is a definitely Pre-order deal.
You don't appear to live in the UK, however, so someone else may be able to help you more. The price near you will most likely be roughly the same.
The American version of Amazon lists it as $34.99, so that's a rough idea of what it may be. Take a look at some other websites, like the site of where you buy your games from, if you don't order online. Then you'll know exactly.