Key point about Amazon and GAME!
They always put a high price for game pre-orders before prices are announced. They do this for everything, including the Xbox One console, which was around £600 ( same as PS4 ) for ages. Its because when you Pre-order, you are guaranteed the lowest price possible, so by putting it deliberately high, it makes the system work easier, they ultimately have to notify you less. Because if a product goes up in price, after the actual cost is announce, then they have to get you to re-affirm the pre order!
This is easy to confirm, as D4 (an episodic title) and Below (and indie title) are both listed for retail release at the same price £54.99. The likelihood of either of the games costing £54.99 is extremely low!
All games definitely won't cost the same as well! For example GTA V will cost around £40 at launch because its a triple A massive game from an established studio, whereas Remember Me Retailed for around £32 at launch, smaller studio and original IP.
Hope that all helps!