Happy Camper has written
Sure. It's not so complicated. First I add a buildattempthook. If someone is trying to build something, the hook will be called. The hook checks if the building is a turret. If it is, it opens a new menu where the builder can select to build a single, double or triple turret. The script then checks if the player has enough money to build. If he has, it deducts the cost from his money and spawns the building. Spawning a building is an instant operation.