The cost of repairing with ZeTa.

[MMagic308 2]

I fly the destroyer ZeTa on two levels: 9 and 12.
After destroying it at level 9, it shows me a message saying that repair is 45k credits. After the battle, at the outpost the repair is already 70k credits and a multiple of this sum. Why such a difference?
If I'm flying ZeTa on level 12, he also shows me 70k credits after destruction and I pay the same amount at the post.