Depends on what part they drill in order to open it. They might drill a hole and use a rigid scope to view the combination wheels line up while turning the dial, then use something called transferring to open it, or they might drill out the fence just to get the lock open, in which case it won't be usable afterwards unless you get a new fence/lever arm from someone's spare parts bucket as it isn't a part you can just buy at a hardware store.
Find a real safe and vault tech not just your corner locksmith who may occasionally work on safes. You don't want someone to spend 2 hours drilling 5 holes into the door before they manage to get it open.
price will be $300-$750 on average.
visit
http://savta.org/ for safe techs near you.
Squelchtone