Gonchi: I hope they add a boxed version at a lower tier, otherwise I think I'll just wait until the game is done to get it.
It would be better if you pledged, even just a little, because that way they get closer to stretch goals, which they have said they will start revealing once they're getting close to a new level of pledges. The only revealed stretch goal so far is the weapon pack, which I don't care too much about, but the later stretch goals might offer more interesting stuff (maybe additional quests for the game, more characters, who knows. Or maybe they can hire more staff and have the game out sooner). Besides, like they've said, the 15 dollar tier gets you the game for nearly half the price it will cost once the game is made. Of course, if you only want the game if you can get it boxed, then...I guess KS won't help you there. But maybe they've decided, that the only boxed versions go to those who pledged 250-350 dollars, and those copies aside, the game will only be sold in digital stores; that way the boxed copies will truly be collector's items. You never know what they might have decided :p
But anyway, like I said, if you really want the game, and a digital copy is fine (you ARE on GOG after all so it shouldn't be a problem), I think you should definitely pledge and help them raise as much money as they can. That way we, the gamers, benefit the most too.