For the buyer it has some advantages. You're going to be buying a vehicle "guaranteed" to be safe. So long as you feel being inspected by a government agency means that.
Once that process has gone through, putting insurance on the vehicle is no different, nor more costly than a normal vehicle.
For the seller, not so much. They have to be familiar with the process. Be sure they can get parts and keep the proper paper trail, all while hopefully turning a profit.
For the buyer it has some advantages. You're going to be buying a vehicle "guaranteed" to be safe. So long as you feel being inspected by a government agency means that.
All that means is it wasn't put back together with stolen parts. A salvage inspection isn't a safety inspect beyond making sure it has a windshield installed, the fenders aren't held on by duct tape, or the door isn't about to fall off.
Most likely it was a trade in at the dealer and due to its age (and accident history) the dealer sent it to auction. Probably gave the customer $200 on the trade-in and maybe got $500-$700 back.
The vehicle could also have been donated, some donation vehicle sales are outsourced to auctions.