Before going for this achievement I would advise getting Jugger-Nog (2,500)
. You may need to open up all the areas since the perk spawns are random, the comm room, fishing hut, doctors quarters and the storage hut.
Best traps to use are the Electric trap in the comm room (1,000 points), the Flogger (750 points) which is near the trip mines (where the bouncy betties used to be) and the Electric trap (1,000 points) inside the fishing hut.
At the start of the round go near the trap inside the comm room and be ready to buy it as soon as the zombies start making there way through. Then move onto the Flogger buy it let it kill one zombie then go to the last trap inside the fishing hut. In total the three traps will cost you 2,750 points.Layout of map