That level of buy-in is not required. You can get a game package with a single starter pack for US$40. The one in the article includes every variant of every vehicle currently in the game or in development or announced as planned. IMO it's for people who just want to support development because it literally removes a bunch of reasons to even play.

It's hard to definitively say if greed has taken over or if they're just trying to fund development as legitimately as possible without a publisher. They have done some groundbreaking things (64 bit coordinate system, object container streaming, etc) and are working in more (replication layer, server meshing, etc). That is why it has been so long and expensive, why the game is still alpha.