13 days ago - Shurenai - Direct link
$15 back in kickstarter. 1,161.8 hours listed on steam. Likely double that from untracked playtimes such as pre-steam version.

Ballparking 2250, I get $15 / 2250 = $0.00666...

And many more hours to come, 'Cause I love the game.
13 days ago - SylenThunder - Direct link
I paid 16.74 for it in Oct 2014.
I currently have 5804 hours according to Steam. That's a bit shy because they didn't track offline play for a couple of years.

$/hour = $0.0028842177808408