> and they turned out to be completely wrong.

There were a lot of assumptions that turned out to be wrong. The chief among them was launch cadence and satellite capture and return missions. When these assumptions changed the cost values changed significantly as well.

> Why should we trust that this time will be different?

Do you understand the details of this specific contract? It's limited to 10 launches. It's structured quite a bit differently than the shuttle program was.

> NASA's own Inspector General says

Yes and did you read the recommendations and follow up from that same report? Or is this just a "haha NASA is dumb" rant that's become common around here?