As part of the Deals of the Week (http://www.game.co.uk/lowdown.aspx?lid=10631&cm_sp=deals-_-topnav-_-pc), this seems to be the best value. Damn cheap with the extra PC content!
Chinatown Wars for cheaper than the iPhone version? Sounds like a deal! Definitely got my order in already.
Speaking of Play.com, they also have Champions Online for £2.99, so if you were curious about that, might be time to give it a try!