Looks like the question of The Order 1886's length will never die. The magazines slammed the game and are claiming 5 hours total, but that's assuming you speedrun it and skip all the video scenes. I streamed myself playing it on Twitch and found it took me about 9 hours in total on my first go.
The game itself is nowhere near deserving of as much hate as its getting. The reviews most quoted are from sites that are not only under fire from GamerGate, but like to nitpick to create "sensationalist" reviews that attract visitors. Look at IGN claiming the latest Pokemon games had "Too much water", and Gamespot sacking one of their reviewers when site advertising was withdrawn due to a review he gave.
The main issue I find is that hardly anyone mentions what is actually IN the game, only its length. Overall it's a fun Gears of War clone with a fantastic steampunk storyline and awesome weapons (such as a Thermite cannon). Not the sort of thing I'd pay £54.99 for, but solid enough at a discount (I got it as part of a £299 PS4 package Argos had on offer last month).
As for the $10/hour equation, I found at 9 hours length and £54.99 price, it comes to about £6.11 ($9.20). However it's 9 fun hours overall.