Stonemeier uses Kickstarter more or less a preorder system, with some higher level donation tiers for absurd perks like your face in the game. KS does not require that your project finish, but it does require backer rewards delivered. The most popular backer reward tiers includes the actual game, priced at basically MSRP.

It's absolutely true that consumers are taking more risks than your average GameStop preorder. Stonemeier has an impeccable record, and so his company reaps the ongoing benefits of that lower delivery risk profile by using KS. Another way to think of this is that you are completely free to avoid project risk by purchasing from a backer via BGG/ebay, but will likely have to pay a premium for it. I imagine some people intentionally preorder two, just to pop one up for sale.