I would guess man hours.

Because it’s going to take time to put those servers back in production. Depending what they did it might have causing outage to external facing customers, which will have a higher impact than internal facing. But with that amount of money, it actually seems fairly low to me so I’m guessing they weren’t public facing servers.

So it was probably the time that it takes to recreate all those servers get everything back up and running, and delayed work caused by the outage.

That’s just my guess though