I know this is an old thread from back in February but,
1: The cost is whatever you are comfortable with. If you wish to set a reserve on these vehicles you may, be aware though that most of the time these vehicles were abandoned for a reason and most likely not worth much. We try to get more than scrap out of every vehicle we can but more often than not its about the same.
2: The titles will be a Certificate of Salvage and be branded Formerly Abandoned. These can still be rebuilt via enhanced inspection.
Special note: these titles are transferable and I would advise you to transfer the title legally prior to releasing the vehicle to a buyer that has plans of repairing the vehicle. Once its off the lot it's still considered your vehicle and will be seen as such legally. A certificate of salvage does not require a notary when being sold to a salvage dealer.