During the kickstarter they sold Duo packs, so presumably they want you to buy two copies. I don't see any two pack deals on Steam or GOG so you have three choices: Wait for a duo deal, buy two copies at full price or buy one copy and stop posting incriminating evidence on the internet.
The digital collector's edition on Steam for 70€ contains two copies of D:OS and it costs 10€ less than two single copies without the extras for 40€ each.
