I'm pretty certain it'd be exactly $23.17 per week - in fact i'd guarantee it! lol!
As ARSN said, u can't expect any real answer as u didn't give much info on specs or what u pay for elec - but joking aside, yes ur cost will clearly rise, though ur not talking thousands extra per month.
The way to work it out is to find the individual Wattage of each item - look up online (or read of side of box if already purchased) to find tech specs listing how many Watts each item uses. (u'll probably have to go to each manufacturers website or if their website is shit & doesn't get technical then email them to ask).
Next find out how much u pay for electricity (ur electricity company is most likely charging u on a Kilowatts Per Hour basis - 1000W's per hour) - so if u have to pay $4 per KwH & ur running a 500W appliance, that appliance will cost $2 per hour to run. If ur running 1500W, it'll cost $6 per hour. (etc, etc) Basically just add up the Wattage of each item u wanna run & see how much it'd cost per hour to run that total. Then multiple that by the amount of hours u intend to leave stuff running (12, 18, 24???!) and u got ur daily figure.
Also, i appreciate that if u aint into elec that even working out ur KwH per hour cost may seem abit too clinical & detached, so u could also get a real-life comparision & make it relate to what u know. After checking out how much Watts ur grow equipment uses, then check out the Wattage of ur normal stuff like TV's, computers, kettles, irons, etc - u'll start seeing how some items use more than others & some are quite similiar in useage, so as a basic comparision u can say running a 600W light would be like running 2 Plasma TV's for the same time period, etc, etc - just another possibly easier way of visualising it.
Best of luck dude!
