We have found that having two layers of mesh, or one of chicken wire and the other sheep mesh, is something of a death trap, perhaps not for the dachsies, but for lambs or poultry on the other side. It is almost impossible to get chicken wire really taut, just because of the way it's made, so it becomes a series of hanging traps - heads can get through but not back.
Sorry I can't help with costs as we've always done our own, but perhaps a single person fencing business would be the way to go. I would think that the costs reflect where you are and how many fencing providers there are in the area. Get at least 3 estimates before committing yourself to such a cost. Perhaps the price is higher because of the gates and all those strainers needed - can be hard work if your ground is rocky like ours.