Well... the cheapest
was actually in my link.
(I know GMG have it without the DLC for $45, but boxed + DLC + shipping is still cheaper if you can wait a week)
I'm not suggesting for you to cancel and re-order from the UK. That link was just an example of how cheap it is already, and it's likely that other retailers to have it cheaper before release. And given the team's pedigree, will it just be a box with a Steam code and a DLC code and nothing else? Might be artbooks and soundtracks etc, like Dark Souls and Endless Space.
I'd certainly advise people to wait on this one.