Why Kickstarter? You have a publisher with Daedalic. And i can preorder the german box version for ~45€ (kickstarter: 65$+12$=77$).
Larian is self publishing (and self funding) Original Sin and Dragon Commander. Daedalic is a distributor.
As for why Kickstarter, Larian wants to hire a secondary design team to add a lot of depth and diversity to the game (more interactivity, quests, choices/consequences, NPCs, locations, etc). Possibilities for stretch goals include non-human playable characters, backstories and personalities added for henchmen, additional map areas, etc. The kickstarter page describes this in more detail. It looks to be a very good game as it is now, IMNSHO; with the additional funding it can be even better.
