This is the fastest way to get the zombie shield on round 1 with a little help from the zombie gods and the fence part not being by the number switch. You need 6,750 points in expenses and this method will get you 7,280 points.
- First room, hit 2x and shoot zombie legs 8 times, killing them with the knife, doing this to 5 zombies leaving 1 zombie left, giving you 2,600 points
- Open door and head to afterlife by the shower door and zap the meter to open the showers, the meter to open 2x and jump to the generator that lowers the key (this whole method only works if the key is by the cafe not the warden's office)
- Grab the key and unlock the gate by the washer in the showers and go into AL (afterlife) zapping the meter to turn on the washer
- Turn on the washer and 20 more zombies will spawn
- Go up to the 2x in the cell and stab as many zombies as you can
- When the 2x runs out, shot 8 in the leg followed by a stab (i was able to get 4,680 points bringing my point total to 7,280)
- Go back to the starting room and head upstairs to open the gate toward the electric cherry and gondala (2,000 points to open)
- Go into AL and zap the gondala meter
- Ride the gondala down to the docks (cost 750 points)
- Go to the far side opposite the Thompson and find the dolly
- Unlock the door beside the dogs heads and find the clap on the shelf (cost 1,500 points)
- Unlock the other door (cost 1,500) and check in the corner to your immediate left if the barbed fence piece is there, if not turn around and make a left, then head through the hallway and make a right, if its not there then its in the stair case by the number combination and you will have to start over cause it cost another 1,000 points to open that door.
- Go down to the buildable table by the dogs head and there you go. Zombie Shield built in round 1
Here is a video that shows the step by step procedure from above.
https://www.youtube.com/watch?v=WtCJYaXGnQU