rehh. I am not doing it.
Assassin you may talk to me if you need help coding it.
All it looks like to me is a kill counter that adds money or some shit for each kill. (Kill Counter)
Random Zombie Spawning at special entities in a map. (Player Spawning/NPC Spawning)
Buying things off the walls would be an in map thing. Would have to define an entity/button that takes "money" from the kill counter and ply:Give( "A_gun"). (Ents / Buttons)
HUD to show money, ammo. Talk to me about this one. (HUD's / Draw)
Have fun.
As I said feel free to talk to me.