I'm sorry to hear about your damage.
I am curious as to why the rear axle carrier, differential and fuel tank need to be replaced... is there damage to the subframe (rear axle carrier)? Is there a puncture in the fuel tank? The differential looks to be hanging but is it destroyed? Was it dragged on the road? From the pictures, you have a broken diff bolt - a common problem with 6mt e9x m3s. The bolt is a couple bucks to replace. Unless your subframe is bent/damaged, I don't know why everything has to be replaced.