Pricing between UK and Canada

[jugolicious]

I have a question about the pricing between UK and Canada games, especially for Remakes (prices from Zavvi.com).

Zavvi.com
These games haven't even came out yet, and the HD collections are coming out in 2012, but the prices are discounted heavily already!
Silent Hill HD Collection - £17.85
Zone of the Enders HD Collection - £17.85
Child of Eden PS3 - £14.85

Canada usually has these remakes at $39.99 MSRP

Can anyone tell me why is the price difference so huge for a game that hasn't even come out yet? Thanks!