I think the clue is in the title. 1000W that is 18 kilowatt hours a day. I pay 9.17p per kilowatt hour here in the uk which translates to
18 * 0.0917 = £1.65 ($2.48 ) / day
during an 18 hour vegetative cycle. This is using the nominal rating for the bulb, it'll actually use more, but how much...