Planning. Draw your design get the measurement. price of wood adds up fast, especially when you buy extra. it shouldnt cost more then about 300-400 for the wood for an 8foot by 2 foot pit. not including the tiles, terrain, and whatever else you want to put in the pit. also a good idea to make it in sections when you can lift a door to get to a tile, that way you have the entire 8x2 top to do footsteps etc if needed.