Construction interface problem

[Construction interface problem]

using the contruction module i have gotten to the stage where i can place buildings like you would in warfare, however placing a building doesnt deduct from your funds, even though i set its cost in the BIS_COIN_items variable. none of the other commands listed here help:

http://community.bistudio.com/wiki/Construction_Interface

anyone know of anyother commands or what i'm doing wrong. i have set my construction vars like so:

_coin = _this select 0; (BIS_coin_0)

_coin setvariable ["BIS_COIN_categories",["Base", "Defence"]]; 

_coin setvariable ["BIS_COIN_items",
[
	//--- Class, Category, Cost or [fundsID,Cost], (display name)
	["USMC_WarfareBBarracks","Base",200],
	["BTR90_HQ_unfolded","Base",100],
	["USMC_WarfareBLightFactory","Base",200]
]
];

_coin setvariable ["BIS_COIN_areasize",[50,20]]; 

_coin setvariable ["BIS_COIN_funds",["200"]];

_coin setvariable ["BIS_COIN_fundsDescription",["S"]];

hi pogoman . im a bit lost with this ive created my sqf file, but now im not sure after reading this what im supposed to put in it anymore. can you give me a run down of what youve done so far or a demo mission? please help arrrgghh!!